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06: HashMap & HashSet and how do they internally work? What is a hashing function?

Java equals vs hashCode

HashMap & HashSet are not only one of the frequently used data structures, but also one of the popular interview topics. Q1. How does a HashMap store data? A1. As key/value pairs. You can store and retrieve values with the keys. … Read more ›...

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5 Java Object class methods interview questions & answers

Q1. What are the non-final methods in Java Object class, which are meant primarily for extension? A1. The non-final methods are equals( ), hashCode( ), toString( ), clone( ), and finalize( ). These methods are meant to be overridden. … Read more ›...

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8 Java immutable objects interview questions & answers

Best Practice: “Classes should be immutable unless there’s a very good reason to make them mutable….If a class cannot be made immutable, limit its mutability as much as possible.” — by Joshua Bloch Q1. What is an immutable object? Q2. Immutable objects are objects whose state (the object’s data) cannot...

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Java enum interview questions & answers

Covers the power of enumand 3 design patterns that can be applied with the help of enums. Q1. Why is it a best practice to use enums over static final int or String constants? A1. 1) static final allows invalid values. … Read more ›...

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Java serialization, cloning, and casting interview Q&A

Q1. Which Java interface must be implemented by a class whose instances are transported via a Web service? a. Accessible b. BeanInfo c. Remote d. Serializable A1. Answer is “d”. Q2. What is serialization? A2. … Read more ›...

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Mocks, stubs, domain, and anemic objects interview Q&A

Q1. What are mock objects? A1. Mock objects are used in unit testing to ensure that your tests don’t fail due to volatility of the data changes. There are mocking frameworks like EasyMock, Mockito, and PowerMock. … Read more ›...

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Object equals Vs == and pass by reference Vs value

Q1. What is the difference between “==” and equals(..) method when comparing 2 objects?
A1.It is important to understand the difference between identity (i.e. ==) comparison, which is a shallow comparison that compares only the object references, and the equals( ) comparison,

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Java FAQs to Fast-track & Go places

250+ Java Interview FAQs 🔥
FAQs - Prepared?
How to prepare to succeed in Java job interviews?
12 things to know about job interviews
FAQs - Ice Breaker
5 - 8 real life examples of SAR technique
15 Ice breaker interview Q&As asked 90% of the time
07: 20+ Pre interview refresher on tools
04: Can you think of a time where you ...?
10+ Know your industry Q&As
1 - 4 real life examples of Situation-Action-Result (i.e. SAR) technique
FAQs - Core Java
Java Generics in no time "? extends" & "? super" explained with a diagram
17 FAQ Java Collection interview Q&As
00: Top 50+ Core Java interview questions answered - Q1 to Q10
00: Top 50+ Core Java interview questions answered - Q11 to Q23
00: Top 50+ Core Java Interview questions answered - Q43 to Q54
00: Top 50+ Core Java interview questions answered - Q37 to Q42
00: Top 50+ Core Java interview questions answered - Q24 to Q36
02: 5 Java multithreading scenarios interview
15+ Java multithreading interview Q&As
Q1 - Q10 Java OOPs interview Q&As
6 Java Modifiers every interviewer likes to Quiz you on
02: 10 Java String class interview Q&As
FAQs - JEE
Client-side & Server side view technologies Q&As
Q29-Q53: Top 50+ FAQ JEE Interview Q&As
Q01-Q28: Top 50+ FAQ JEE interview Q&As
06: Web design patterns MVC2, MVP, MVVM & MVW
9 JNDI and LDAP interview Q&A
02: JavaScript mistakes interview Q&As
16 FAQ JMS interview Q&As
12 FAQ JDBC interview Q&As
04: 7 JSP interview questions and answers
03: 21+ Java Servlet interview Q&As
01: 12 Web basics every Java web developer must know
8 JEE (i.e. Java EE) Overview interview Q&As
FAQs - Web Services
01: Q13 "12 Rules" for REST API design & development
01: Q07 - Q12 Java Micro & Web services Interview Q&As
05: REST Service URI conventions with Spring MVC
06: RESTful Web services and HATEOAS Q&A
02: 6 Java RESTful Web services Interview Q&As
09: 11 SOAP Web service interview Q&As
01: 6 must know Java Web Services Interview Q&As
FAQs - AWS
15+ AWS Services overview interview Q&As
15 EC2 instances interview Q&As
18 Amazon S3 interview Q&As
02: AWS Identity & Access Management (i.e. IAM) interview Q&As
01: AWS Q&As on VPC, Subnets, Availability Zones, VPN, Route tables, NACLs & Security Groups
FAQs - Microservices
02: 7+ Java architectural patterns interview Q&As - Part 2
10+ Domain Driven Design (i.e. DDD) Interview Q&As
Spring Cloud Microservices interview Q&As
7 Apache Kafka architecture interview Q&As
10+ Key Microservices Interview Questions Answered
03: Kubernetes (i.e. Minikube) - deploy a spring boot microservice app
DevOps Kubernetes, Docker & Microservices Q&As
6 Distributed storage & computing systems interview Q&As
17+ DevOps CI/CD Jenkins interview Q&As
Event sourcing & CQRS interview Q&As
01: Q07 - Q12 Java Micro & Web services Interview Q&As
15 Spring Boot interview Q&As
03: 7+ Java architectural patterns interview Q&As - Part 3
16 FAQ JMS interview Q&As
01: 7+ Java architectural patterns interview Q&As - Part 1
FAQs - Architecture
02: 7+ Java architectural patterns interview Q&As - Part 2
04: How to go about designing a medium size JEE app?
03: How would you go about designing an online shopping cart?
03: 7+ Java architectural patterns interview Q&As - Part 3
01: 7+ Java architectural patterns interview Q&As - Part 1
FAQs - Hibernate
Q08 - Q15 Hibernate interview Q&As
Hibernate First & second level cache interview Q&As
8 JPA interview questions and answers
8 Hibernate interview Q&As
FAQs - Spring
Spring Cloud Microservices interview Q&As
11 Spring MVC Interview Q&As
01b: Q08 - Q13 Spring interview Q&As
15 Spring Boot interview Q&As
05: 9 Spring Bean scopes interview Q&A
01: Q01 - Q07 Spring core interview Q&As
04 17 Spring bean life cycles & scopes FAQs
01: Spring DI & IoC interview Q&As
FAQs - Key Areas
02: 15 key considerations for low latency Java
Top 10 causes of performance issues in Java
Monitoring/Profiling Java applications interview Q&A
Flyweight design pattern to improve memory usage & performance
QoS & SLAs interview Q&As on Availability, Serviceability, Fault tolerance & Disaster Recoverability - Non Functional Requirements
8 Java memory management interview Q&As
9 Java Transaction Management Interview Q&As
4 JEE Design Patterns Interview Q&As
5 Java concurrency management interview Q&As
Design pattern intents interview Q&A
12 Java design patterns interview Q&As
15 Security key area interview Q&A for Java developers
4 FAQ Performance tuning in Java interview Q&As
6 Scaling your Java applications interview Q&As
18 Agile Development interview Q&A for Java developers
FAQs - OOP & FP
01: 19 Java 8 Functional Programming FAQs
5 FAQs on transforming your thinking from OOP to FP
Why favour composition over inheritance?
Q1 - Q10 Java OOPs interview Q&As
FAQs - Code Quality
30+ Java Code Review Checklist Items
8+ JMeter performance testing interview Q&As
5 Java unit testing interview Questions and Answers
Ensuring code quality in Java Q&As
FAQs - UML
12 UML interview Q&As
FAQs - SQL
15+ SQL scenarios based interview questions answered
14+ SQL beginner interview Q&As
FAQs - RDBMS
10 ERD (Entity-Relationship Diagrams) Interview Q&As
15 Database design interview Q&As
FAQs - Maven
01: 12 Maven interview Questions & Answers
FAQs - JSON & XML
YAML with Spring & Java Q&As
6 JSON interview Q&As
17 XML basics interview Q&As
FAQs - Unix
Top 10 Linux interview Q&As
Shell script interview Q&As for Java developers
14 Unix interview Q&As for Java developers
FAQs - Regex
8 Regular Expressions (aka Regex) by examples for Java developers
Regular Expressions interview Q&As for Java developers
FAQs - DevOps
DevOps Kubernetes, Docker & Microservices Q&As
4 DevOps interview Q&As
17+ DevOps CI/CD Jenkins interview Q&As
21 Docker DevOps interview Q&As
FAQs - JMeter
JMeter for performance testing REST services with BeanShell
8+ JMeter performance testing interview Q&As
FAQs - GIT
02: 6 More Git interview Q&As
03: Understanding Git terms origin, master, and head
04: Merging Vs rebasing on Git questions and answers
12+ Git Source control must know basics interview Q&As
16+ Tech Key Areas Q&As 🔥
Key Area - Going places
Why low latency & Big Data are high income skills?
00: 16+ Tech Key Areas to go places as a Java Engineer or Architect
Key Area - Ice Breaker
5 - 8 real life examples of SAR technique
30+ Java Code Review Checklist Items
15 slacknesses or lack of experience that can come back & bite you in the back
Ensuring code quality in Java Q&As
04: Can you think of a time where you ...?
3 key "How would you go about ..." Q&As to judge Java experience
1 - 4 real life examples of Situation-Action-Result (i.e. SAR) technique
Key Area - Design Concepts
05: Q19-Q24 How to create a well designed Java application?
01: Q13 "12 Rules" for REST API design & development
Understanding Open/Closed Principle (OCP) from the SOLID OO principles with a Java example
Why does good API design matter?
06: Q25 - Q32 Design principles interview questions & answers for Java developers
6 tips to go about writing loosely coupled Java applications
Why favour composition over inheritance?
Key Area - Judging Experience
05: Q19-Q24 How to create a well designed Java application?
SQLException handling - recoverable & irrecoverable scenarios
02: 15 key considerations for low latency Java
2. Asynchronous processing in Java real life examples - part-2
1. Asynchronous processing in Java real life examples - part-1
12+ FX or Forex Trading questions & answers
10 ERD (Entity-Relationship Diagrams) Interview Q&As
15+ SQL scenarios based interview questions answered
12: 5 Java synchronize & concurrency mgmt scenarios interview Q&As
6 Key considerations in processing large files in Java
Dealing with concurrent modifications in Java
17 Java Coding Tips for job interviews and pre-interview coding tests
30+ SDLC activities you perform as a Java developer
15 Banking & finance domain knowledge interview Q&As
How to perform impact analysis across Java based applications?
02: 5 Java multithreading scenarios interview
3 key "How would you go about ..." Q&As to judge Java experience
11 "In your Java experience" interview questions & answers
18 Java scenarios based interview Q&As for the experienced
7 Java debugging interview questions & answers
SDLC process interview Q&As
Key Area - Best Practices
Can you list 10 JEE best practices from your experience?
9 Java Data structures best practices
Top 5 Core Java Exceptions and best practices
10 Core Java Best Practices with an industry strength code sample
5 Java unit testing interview Questions and Answers
How will you go about improving on the following Java code?
Key Area - Concurrency Mgmt
jvisualvm to debug deadlocks in Java
JConsole for debugging deadlocks in Java
12: 5 Java synchronize & concurrency mgmt scenarios interview Q&As
Dealing with concurrent modifications in Java
02: 5 Java multithreading scenarios interview
5 Java concurrency management interview Q&As
Key Area - Low Latency
06: Capture throughput & latencies with "Metrics Core" tutorial
07: Reactive Programming or Reactor pattern (RP) in Java Interview Q&As
04: Java primitives & objects memory consumption
03: Java GC tuning for low latency applications
02: 15 key considerations for low latency Java
2. Asynchronous processing in Java real life examples - part-2
1. Asynchronous processing in Java real life examples - part-1
01: 9 Java low latency interview questions & answers
03: Understanding Big O notations
9 Java Garbage Collection interview questions & answers
Key Area - CI/CD & DevOps
10 DevSecOps interview Q&As
DevOps Kubernetes, Docker & Microservices Q&As
4 DevOps interview Q&As
Docker DevOps Q&As with Big Data code snippets
9+ CI/CD Docker compose DevOps interview Q&As
17+ DevOps CI/CD Jenkins interview Q&As
21 Docker DevOps interview Q&As
Key Area - Debugging
Key Area - Debug Hibernate
05: Debugging Hibernate & handling 4 common issues
04: Identifying and fixing LazyInitializationException in Hibernate
03: Identifying and fixing NonUniqueObjectException in Hibernate
Key Area - Debug Java
Debugging LinkageErrors in Java
Debugging "NoSuchMethodError" in Java
Remote debugging in Java with Java Debug Wire Protocol (JDWP)
javap for debugging and better understanding some Java concepts with 3 practical examples
jvisualvm to debug deadlocks in Java
JConsole for debugging deadlocks in Java
Debugging Java version issues
Debugging JAR hell issues in Java
5 Ways to debug thread-safety issues in Java
Debugging like a pro with eclipse IDE tutorial for Java developers
7 Java debugging interview questions & answers
Key Area - Debug JEE
Debugging connection refused issues in Java with 9 tips
Debugging java.security.cert.CertificateException: Certificates do not conform to algorithm constraints
Chrome Postman to test and debug RESTful Web Services
Debugging SSL issues in Java & tools to debug
02: HTTP basics on headers, MIME types, & cookies for Java developers
Key Area - Debug Spark
15+ Apache Spark best practices, memory mgmt & performance tuning interview FAQs - Part-2
Spark understanding DAG for tuning performance interview Q&As
15+ Apache Spark best practices, memory mgmt & performance tuning interview FAQs - Part-1
Finding your way around YARN and Spark on Cloudera
Debugging Spark applications written in Java locally by connecting to HDFS, Hive and HBase
Remotely debugging Spark submit Jobs in Java
Key Area - Debug Spring
07: Debugging Spring Transaction Management
06: Debugging NoSuchBeanDefinitionException in Spring
Key Area - Design Patterns
Key Area - GoF Design
14: Singleton design pattern in Java & 5 key follow up Interview Q&As
Proxy design pattern in Java with service retry example
Why do Proxy, Decorator, Adapter, Bridge, and Facade design patterns look similar? What are the differences?
Java ExecutorService with strategy design pattern to execute concurrently & sequentially
Flyweight design pattern to improve memory usage & performance
Builder pattern and immutability in Java
Design pattern intents interview Q&A
12 Java design patterns interview Q&As
Key Area - JEE Design
06: Web design patterns MVC2, MVP, MVVM & MVW
4 JEE Design Patterns Interview Q&As
EIP
Key Area - Exception Handling
Java String & Array limitations and OutOfMemoryError
SQLException handling - recoverable & irrecoverable scenarios
Top 5 Core Java Exceptions and best practices
Java exception handling interview questions and answers
Key Area - Memory Mgmt
Java String & Array limitations and OutOfMemoryError
02: jvisualvm to detect memory leak - a quick tutorial style Java demo
01: jvisualvm tutorial to sample Java heap memory
javap, jps, jmap, and jvisualvm tutorial - analyzing the heap histogram
6 Key considerations in processing large files in Java
10: 8 Java Maps & Caching Data in Java Interview Q&As
Monitoring/Profiling Java applications interview Q&A
8 Java memory management interview Q&As
9 Java Garbage Collection interview questions & answers
Key Area - Performance
Processing large files efficiently - BigData & Hadoop - part 3
02: 15 key considerations for low latency Java
javap, jps, jmap, and jvisualvm tutorial - analyzing the heap histogram
Processing large files efficiently in Java - multi-threaded code - part 2
6 Key considerations in processing large files in Java
Understanding service and socket timeouts in Java enterprise applications
10: 8 Java Maps & Caching Data in Java Interview Q&As
JMeter for performance testing REST services with BeanShell
8+ JMeter performance testing interview Q&As
Top 10 causes of performance issues in Java
Monitoring/Profiling Java applications interview Q&A
4 FAQ Performance tuning in Java interview Q&As
9 Java Garbage Collection interview questions & answers
Key Area - Scalability
02: 15 key considerations for low latency Java
Straight Through Processing, OLTP, Data warehousing & OLAP
6 Scaling your Java applications interview Q&As
Key Area - SDLC
04: Merging Vs rebasing on Git questions and answers
05: Git & Maven for releasing software artifacts Q&A
30+ SDLC activities you perform as a Java developer
Source control system and subversion (aka SVN) Q&A
Java BDD (Behavior Driven Development) interview Q&A
SDLC process interview Q&As
18 Agile Development interview Q&A for Java developers
Key Area - Security
AWS Web Application Security Q&As
6 Authentication Protocols Interview Q&As - LDAP, Kerberos, OAuth2 & SAML
6 LDAP Interview Q&As
12 Kerberos interview Q&As
Preventing XSS attacks in Java
Injection attack prevention Q&A
Session Hijacking prevention Questions & Answers
Debugging java.security.cert.CertificateException: Certificates do not conform to algorithm constraints
10 Encryption and Decryption interview Q&As
HTTP Basic Authentication Interview Q&A for Java developers & architects
SSL in Java with Keytool to generate public-private key pair
Debugging SSL issues in Java & tools to debug
Understanding service and socket timeouts in Java enterprise applications
Spring security tutorial
SSL and truststore vs keystore for Java developers
Security holes & how to fix them interview Q&A
15 Security key area interview Q&A for Java developers
Key Area - Productivity Tools
Splunk to analyse Java logs and other machine data
Chrome Postman to test and debug RESTful Web Services
Debugging SSL issues in Java & tools to debug
Unix Sed commands for Java developers
Unix history commands for Java developer productivity
sed and awk to write shell scripts for Java developers
Top 7+ Java productivity tools that make your life easier as a Java developer
Debugging JAR hell issues in Java
Unix script to archive files for auditing
Power of SQL as a productivity tool
Notepad++ to construct SQL where clause
Notepad++ productivity tips with SQL trigger code example
Notepad++ beginner tutorial
Top 10 Eclipse short-cut keys every Java developer using eclipse IDE must know
Debugging like a pro with eclipse IDE tutorial for Java developers
Source control system and subversion (aka SVN) Q&A
Handy DOS commands for Java developers
How to perform impact analysis across Java based applications?
JMeter beginner tutorial
Unix tutorial with MobaXterm
Unix remoting interview Q&A for Java developers
14 Unix interview Q&As for Java developers
Key Area - Transaction Mgmt
07: Debugging Spring Transaction Management
Spring, JavaConfig (@Configuration), and TransactionManager
Transaction management in SQL -- Sybase example
9 Java Transaction Management Interview Q&As
JTA interview Q&A
Key Area - QoS & SLAs
Splunk to analyse Java logs and other machine data
Auditing database record changes in Oracle
How do you monitor the JVM?
Understanding service and socket timeouts in Java enterprise applications
15 slacknesses or lack of experience that can come back & bite you in the back
Auditing, data retention and archiving interview Q&A
Monitoring/Profiling Java applications interview Q&A
QoS & SLAs interview Q&As on Availability, Serviceability, Fault tolerance & Disaster Recoverability - Non Functional Requirements
100+ Architect Interview FAQs 🔥
Architecture - Patterns
Multi-tenant Architecture Interview Q&As
02: 7+ Java architectural patterns interview Q&As - Part 2
10+ Key Microservices Interview Questions Answered
Event sourcing & CQRS interview Q&As
01: Q07 - Q12 Java Micro & Web services Interview Q&As
04: How to go about designing a medium size JEE app?
03: How would you go about designing an online shopping cart?
03: 7+ Java architectural patterns interview Q&As - Part 3
01: 7+ Java architectural patterns interview Q&As - Part 1
Architecture - How to
03: How would you go about designing an online shopping cart?
How to become a software architect?
3 key "How would you go about ..." Q&As to judge Java experience
18 Java scenarios based interview Q&As for the experienced
SDLC process interview Q&As
Architecture - AWS
Multi-tenant Architecture Interview Q&As
AWS Web Application Security Q&As
15+ AWS Services overview interview Q&As
15 EC2 instances interview Q&As
18 Amazon S3 interview Q&As
02: AWS Identity & Access Management (i.e. IAM) interview Q&As
01: AWS Q&As on VPC, Subnets, Availability Zones, VPN, Route tables, NACLs & Security Groups
Architecture - Distributed
Spring Cloud Microservices interview Q&As
10+ Key Microservices Interview Questions Answered
6 Distributed storage & computing systems interview Q&As
Event sourcing & CQRS interview Q&As
19: Q125 - Q130 Apache Zookeeper interview Q&As
5 Spark streaming & Apache storm Interview Q&As
9 Java Transaction Management Interview Q&As
Architecture - Microservices
10+ Domain Driven Design (i.e. DDD) Interview Q&As
Spring Cloud Microservices interview Q&As
7 Apache Kafka architecture interview Q&As
10+ Key Microservices Interview Questions Answered
DevOps Kubernetes, Docker & Microservices Q&As
6 Distributed storage & computing systems interview Q&As
Event sourcing & CQRS interview Q&As
01: Q13 "12 Rules" for REST API design & development
01: Q07 - Q12 Java Micro & Web services Interview Q&As
QoS & SLAs interview Q&As on Availability, Serviceability, Fault tolerance & Disaster Recoverability - Non Functional Requirements
Architecture - QoS
QoS & SLAs interview Q&As on Availability, Serviceability, Fault tolerance & Disaster Recoverability - Non Functional Requirements
Architecture - ERD
10 ERD (Entity-Relationship Diagrams) Interview Q&As
Architecture - ETL
08: Q71 - Q75 ETL/ELT on BigData Interview Q&As
05: ETL & ELT architecture interview Q&As
Architecture - Low Latency
Why low latency & Big Data are high income skills?
02: 15 key considerations for low latency Java
2. Asynchronous processing in Java real life examples - part-2
1. Asynchronous processing in Java real life examples - part-1
Architecture - UML
12 UML interview Q&As
40+ Code Quality - Q&As ✍
Code Quality - Automation
Selenium and Web Driver Interview Questions and Answers
Code Quality - Code Coverage
Jacoco for unit test coverage with SonarQube tutorial
Maven and Cobertura Tutorial
Code Quality - FAQs
30+ Java Code Review Checklist Items
8+ JMeter performance testing interview Q&As
5 Java unit testing interview Questions and Answers
Ensuring code quality in Java Q&As
Code Quality - Profiling
02: jvisualvm to detect memory leak - a quick tutorial style Java demo
01: jvisualvm tutorial to sample Java heap memory
jvisualvm to debug deadlocks in Java
Code Quality - Performance Test
JMeter for performance testing REST services with BeanShell
8+ JMeter performance testing interview Q&As
Code Quality - Unit Testing
Code Quality - BDD
jBehave and BDD example
jBehave with tabular story data
jBehave and jUnit for BDD
Java BDD (Behavior Driven Development) interview Q&A
Code Quality – Testing DAOs
Unit Test Hibernate - DAO Layer with JPA, Spring & HSQLDB
Unit Test Hibernate - DAO Layer with Spring & HSQLDB
Part #3: JPA Hibernate Spring Maven Eclipse Tutorial - testing data access with HSQLDB
Unit Testing Data Access Logic in Java
Code Quality – JUnit Spring
01: JUnit with Mockito step by step
06: Mockito & PowerMock for mocking static methods
05: Mockito & PowerMock partially mocking private methods with @Spy
04: Mockito partially mocking with @Spy
03: Mockito to fully mock the DAO layer
02: Unit testing with JUnit, Mockito & Spring
Code Quality – JUnit Web
Spring Controller Unit Testing
Unit Testing Servlet filter with Mockito
Code Quality - Spring TXN
Integration Unit testing Spring Transaction Management
Unit testing Spring Transaction Management
JUnit with Hamcrest
Spring Boot in unit testing - 6 things you must know
5 Java unit testing interview Questions and Answers

Big Data Engineer FAQs

300+ Big Data Interview FAQs 🔥
Big Data - Data Warehouse
Data categories in Data warehouse & Data lake
00: 13 Data Warehouse interview Q&As - Fact Vs Dimension, CDC, SCD, etc
05: ETL & ELT architecture interview Q&As
Straight Through Processing, OLTP, Data warehousing & OLAP
Big Data - Overview
Data categories in Data warehouse & Data lake
00: Data Lake Vs. Data Warehouse Vs. Delta Lake
6 Distributed storage & computing systems interview Q&As
16: Q114 - Q115 CAP theorem interview Q&As
01: Lambda, Kappa & Delta Data Architectures Interview Q&As - Overview
08: Q71 - Q75 ETL/ELT on BigData Interview Q&As
05: Q37-Q41 - Data lake & metadata interview Q&As
02: Q7 - Q15 Hadoop overview & architecture interview Q&As
00: Q1 - Q6 Hadoop based Big Data architecture & basics interview Q&As
Big Data - HDFS
More HDFS & NameNode interview Q&As
18: Q121 - Q124 Choosing between HDFS & AWS S3 for BigData projects interview Q&As
12: Q92 - Q97 Hadoop file formats and how to choose
11: Q88 - Q91 Read-Write Vs Append-Only File Systems
07: Q62 - Q70 HDFS blocks Vs. splits & Spark partitions Interview Questions & Answers
Big Data - Kafka
7 Apache Kafka architecture interview Q&As
Big Data - Spark SQL
Spark SQL joins & performance tuning interview questions & answers
10 Spark SQL Interview Q&As
17: Spark interview Q&As with coding examples in pyspark (i.e. python)
06: Learn how to access Hive from Spark via SparkSQL & Dataframes by example
Big Data - SQL
SQL querying Temporal tables & SCD Type 2
Common Table Expressions (i.e. CTE) in SQL using the "WITH" clause
SQL window function for analytics interview questions answered
SQL retrieving the latest records interview Q&As
15+ SQL scenarios based interview questions answered
Big Data - MapReduce
03: Q16 - Q26 Hadoop MapReduce interview questions & answers
Big Data - Hive
Q08- Q12 Scenarios Based Hive Query Language (i.e. HQL) Interview Q&As
Q01 - Q07 Scenarios Based Hive Query Language (i.e. HQL) Interview Q&As
Apache Hive for Slowly Changing Dimension (i.e. SCD) interview Q&As
09: Q76– Q88 Apache Hive partitioning, bucketing, map join, skewed data, vectorization & denormalization interview Q&As
13: Q98 - Q104 Apache Hive Basics Interview questions & answers
Big Data - Data Science
05: Linear regression outputs, null hypothesis, t-test & p-value interview Q&As
03: Simple Linear Regression interview Q&As
04: Residuals, Cost/Loss functions, R-squared & Gradient Descent interview Q&As
02: Cleansing & pre-processing data in BigData & machine learning with Spark interview Q&As
01: Q01 - Q07 General Big Data, Data Science & Data Analytics Interview Q&As
Big Data - Impala
10+ Apache Impala Interview Q&As
Big Data - AWS
18 Amazon S3 interview Q&As
Amazon Athena, Redshift, Redshift spectrum & EMR Presto Q&As
5 Amazon EMR Vs. Cloudera interview Q&As
12 Amazon Redshift interview Q&As
21: Q138 - Q142 AWS data lakes overview Interview Q&As
18: Q121 - Q124 Choosing between HDFS & AWS S3 for BigData projects interview Q&As
Big Data - Spark
Spark interview Q&As with coding examples in Scala – part 9
Spark interview Q&As with coding examples in Scala – part 8
Spark interview Q&As with coding examples in Scala – part 7
Spark interview Q&As with coding examples in Scala – part 6
Spark interview Q&As with coding examples in Scala – part 5
Spark interview Q&As with coding examples in Scala – part 4
Spark interview Q&As with coding examples in Scala – part 3
Spark interview Q&As with coding examples in Scala – part 2
Spark interview Q&As with coding examples in Scala - part 1
00: Apache Spark eco system & anatomy interview Q&As
15+ Apache Spark best practices, memory mgmt & performance tuning interview FAQs - Part-2
Spark understanding DAG for tuning performance interview Q&As
02: Cleansing & pre-processing data in BigData & machine learning with Spark interview Q&As
15+ Apache Spark best practices, memory mgmt & performance tuning interview FAQs - Part-1
17: Spark interview Q&As with coding examples in pyspark (i.e. python)
Debugging Spark applications written in Java locally by connecting to HDFS, Hive and HBase
15: Q109 - Q113 Spark RDD partitioning and "mapPartitions" interview questions & answers
14: Q105 - Q108 Spark "map" vs "flatMap" interview questions & answers
12 Apache Spark getting started interview Q&As
Big Data - Spark streaming
8 Spark streaming interview Q&As
5 Spark streaming & Apache storm Interview Q&As
Big Data - NoSQL
10: Q80 - Q87 HBase Schema Design Interview Q&As
06: Q51 - Q61 HBase Interview Questions & Answers
Big Data - Sqoop, Flume & Nifi
13 Apache Sqoop interview Q&As
10+ Apache NiFi interview Q&As
05: Q37 – Q50 Apache Flume interview questions & answers
Big Data - security
Big Data - governance & metadata management interview Q&As
6 LDAP Interview Q&As
12 Kerberos interview Q&As
Big Data - Yarn, Zookeeper
5 Apache YARN interview Q&As
20: Q131 - Q137 FAQ Apache Solr with HDFS interview questions & answers
19: Q125 - Q130 Apache Zookeeper interview Q&As
Finding your way around YARN and Spark on Cloudera
Big Data - Governance
Big Data - governance & metadata management interview Q&As
140+ Scala Interview FAQs
Scala FAQs
What are the uses of underscore i.e _ in Scala?
01A: Scala FP basics: First-class function, higher order function, statements Vs expressions, immutability & recursion
01: Scala Functional Programming basics - pure functions, referential transparency, side effects, etc
01E: Scala Factory Method Pattern & Trait Vs Abstract classes
01D: Scala Class Vs. Object and Companion object interview Q&As
15B: Scala Functors Interview Q&As by example
11A: Scala values, proper types, first order types & higher kinded types
02B: Currying, partial application & functional composition in Scala
21: Q121 - Q124 Scala Extractor Interview Q&As
20: Q114 – Q120 Scala fold vs reduce Q&As
19: Q109 - Q113 Scala ADT (Algebraic Data Types) Interview Q&As
18: Q104 - Q108 Scala typeclass pattern for decoupling with polymorphism
17: Q99 – Q103 Scala applicatives & scalaz interview Q&As
14: Q84 - Q87 Category Theory With Scala Interview Q&As
16: Q93 – Q98 Scala monads interview Q&As
15: Q88 – Q92 Scala Functors Interview Q&As
13: Q81 - Q83 Scala monoids interview Q&As
12: Q78 - Q80 Recursion in Scala Q&As explained with diagrams
11B: Q71 - Q77 - Scala type Parameterization & variance interview Q&As
10: Q66 - Q70 Pattern matching in Scala Interview Q&As
09: Q59 - Q65 Higher Order Functions in Scala Interview Q&As
08: Q49 - Q58 Scala Implicits Interview Q&As
07: Q41 - Q48 Scala Async and Actor System Interview Q&As
06: Q33 – Q40 Scala Futures and Promises Interview Q&As
05: Q27 - Q32 Scala idioms Q&As on Option-Some-None, Try-Success-Failure and Either-Left-Right
04: Q19 - Q26 Scala Data Structures basics interview questions & answers
03: Q13 – Q18 Scala FP combinators interview questions & answers
02: Q6 - Q12 Scala FP currying, closures & partial functions interview Q&As
01C: Q1 - Q6 Scala interview Q&As on Functional Programming
Scala way of coding
16: Coding Scala Way – Scala concurrency styles
15: Coding Scala Way – Scala concurrency & closure vs function definition
14: Coding Scala Way – Scala concurrency with Future
12: Coding Scala Way - Actors with Akka "Ask Pattern" - Part 2
13: Coding Scala Way - 2 Actors with Akka - part 3
11: Coding Scala Way - Actors with Akka - part 1
10: Coding Scala Way - groupBy, mapValues & identity
09: Coding Scala Way - Fibonacci Series
08: Coding Scala Way - Recursion & Higher Order Function
07: Coding Scala Way – Regular Expressions
3 Reasons Why I started Learning Scala
06: Coding Scala Way - Reduce & Compose functions
05: Coding Scala Way - FP concepts
04: Coding Scala Way – Null checks with Option-Some-None
03: Coding Scala Way – Lazy Eval
02: Coding Scala Way - Recursion & Iterator in FP
01: Coding "Java way in Scala" Vs "Scala way in Scala"
80+ Big Data Tutorials
BDT - ⏯ Starting with Big Data
01: Databricks getting started - Spark, Shell, SQL
⏯ 03: Java program to work with HDFS
⏯ 02: Hue and terminal window to work with HDFS
09: Docker Tutorial: Getting started with Hadoop Big Data on Cloudera quickstart
01A: Spark on Zeppelin - Docker pull from Docker hub
BDT - Starting with Spark & Scala
10. Setting up & getting started with Hive
09. Getting started with Spark & Hadoop - client mode on local & cluster mode on yarn
08. Setting up & getting started with Hadoop on Mac
07: Getting started with Spark-submit
06: Setting up Spark-shell on Mac & getting started
05: Setting up & getting started with Spark local mode with Sbt & Scala
04. Setting up & getting started with sbt
03. Setting up Scala and Spark with Maven
02. Setting up Scala IDE & using Maven plugins for Java developers
01. Setting up Scala & practicing the concepts via REPL the Scala way for Java developers
BDT - Starting with Python
02: Getting started with conda on Mac OS
01: Getting started with Python on Mac OS
BDT - Kafka
03: Apache Kafka Connector Tutorial
02: Apache Kafka multi-broker cluster tutorial
01: Getting started with Apache Kafka on Mac tutorial
BDT - Pig
3. Apache Pig: XPath for XML
2. Apache Pig: Regex (Regular expressions)
1. Apache Pig Getting started
BDT - Apache Storm
02: Simple Apache Storm application running on a single node local cluster
02: Simple Apache Storm application running inside Eclipse in a local cluster
01: Installing & getting started with Apache Storm on Cloudera quickstart
BDT - Spark Scala on Zeppelin
13: Spark on Zeppelin – Dataframe date & timestamp
12: Spark on Zeppelin - Dataframe pivot
11: Spark on Zeppelin - Dataframe groupBy, collect_list, explode & window
10: Spark on Zeppelin - union, udf and explode
09: Spark on Zeppelin - convert DataFrames to RDD and RDD to DataFrame
08: Spark on Zeppelin - convert DataFrames to RDD[Row] and RDD[Row] to DataFrame
07: Spark on Zeppelin - window functions in Scala
06: Spark on Zeppelin - RDD operation zipWithIndex
05: Spark on Zeppelin - semi-structured log file
04: Spark on Zeppelin - DataFrame joins in Scala
03: Spark on Zeppelin - DataFrame Operations in Scala
02: Spark on Zeppelin - read a file from local file system
01A: Spark on Zeppelin - Docker pull from Docker hub
01B: Spark on Zeppelin - custom Dockerfile
BDT - Cloudera
⏯ 01: Cloudera Manager Tutorial
Before running a Spark job on a YARN cluster in Cloudera and about the Spark history server
Understanding Cloudera Hadoop users
BDT - Cloudera on Docker
31: Docker Tutorial: Apache Spark streaming in Scala with Apache Kafka on Cloudera quickstart
30: Docker Tutorial: Apache Spark streaming in Python 3 with Apache Kafka on Cloudera quickstart
29: Docker Tutorial: Apache Kafka with Python 3 on Cloudera quickstart
28: Docker Tutorial: Apache Spark streaming with Kafka in Java on Cloudera quickstart
27: Docker Tutorial: Apache Kafka with Java API on Cloudera quickstart
26: Docker Tutorial: Apache Kafka install, create topic & publish message on Cloudera quickstart
25: Docker Tutorial: HBase (i.e. NoSQL) Java API on Cloudera quickstart
24: Docker Tutorial: HBase (i.e. NoSQL DB) Shell on Cloudera quickstart
23: Docker Tutorial: Apache Spark (spark-submit) in Python 3 with virtual env on Cloudera quickstart
22: Docker Tutorial: Apache Spark (spark-submit) in Python 2.6 on Cloudera quickstart
21: Docker Tutorial: Apache Spark (spark-submit) in Scala on Cloudera quickstart
20: Docker Tutorial: Apache Spark (spark-submit) in Java on Cloudera quickstart
19: Docker Tutorial: Apache Spark SQL - on Cloudera quickstart
18: Docker Tutorial: sqoop export - on Cloudera quickstart
17: Docker Tutorial: sqoop import - on Cloudera quickstart
16: Docker Tutorial: Apache Spark (spark-shell) & parquet-tools – csv to parquet on Cloudera quickstart
15: Docker Tutorial: Hive & parquet-tools - csv to parquet on Cloudera quickstart
14: Docker Tutorial: Hive (via beeline) on Cloudera quickstart
13: Docker Tutorial: Apache Spark (spark-shell & pyspark) on Cloudera quickstart
12: Docker Tutorial: Hadoop Big Data configuration files on Cloudera quickstart
11: Docker Tutorial: Hadoop Big Data CLIs on Cloudera quickstart
10: Docker Tutorial: Hadoop Big Data services & folders on Cloudera quickstart
09: Docker Tutorial: Getting started with Hadoop Big Data on Cloudera quickstart
BDT - File Formats
07: Avro IDL (e.g. avdl) to Java objects & Avro Schemas (i.e. avsc) tutorial
06: Avro Schema evolution tutorial
01b: Convert XML file To Sequence File – writing & reading – Hadoop File System (i.e HDFS)
05: Convert XML file To an Avro File with avro-maven-plugin & Apache Spark
04: Convert XML file To an Avro File with Apache Spark – writing & reading
03: Convert XML file To an Avro File - writing & reading
02: Convert XML file To Sequence File with Apache Spark - writing & reading
01a: Convert XML file To Sequence File - writing & reading - Local File System
BDT - Spark on Docker
08: Apache Spark standalone cluster on Docker to read from AWS S3 bucket & write to MySQL database
07: Apache Spark standalone cluster on Docker to read from & write to AWS S3 bucket
06: Apache Spark standalone cluster on Docker to read from AWS S3 bucket
05: Apache Spark local mode on Docker to read from AWS S3 bucket
04: Apache Spark cluster – Docker compose tutorial with Java, Maven & spark-submit
03: Apache Spark cluster - Docker compose tutorial with Java, Maven & spark-shell
02: Apache Spark - local mode on Docker tutorial with Java & Maven
01: Docker tutorial with Java & Maven
BDT - Flume
02: Apache Flume with Custom classes for JMS Source & HDFS Sink
01: Apache Flume with JMS source (Websphere MQ) and HDFS sink
BDT - Hadoop HDFS
05: Create or append a Sequence file to HDFS – Hadoop API tutorial
04: Create new or append to an existing AVRO file tutorial
03: Create or append a file to HDFS - Hadoop API tutorial
02: Java to write from/to Local to HDFS File System
01: Apache Hadoop HDFS Tutorial
BDT - HBase (NoSQL)
5. HBase atomic operations by examples
4. Setting up HBase with zookeeper to be used in Java via maven project
3. Understanding HBase (NoSQL) database basics in 7 steps
2. HBase Shell commands
1. HBase Tutorial Getting Started
BDT - Hive (SQL)
13: Q98 - Q104 Apache Hive Basics Interview questions & answers
BDT - Hadoop & Spark
15: Spark joins with Dataframes & SQLContext
14: Spark joins with SQLContext & JavaPairRDD
13: Spark inner & outer joins in Java with JavaPairRDDs
12: XML Processing in Spark with XmlInputFormat
02a: Learn Spark writing to Avro using Avro IDL
11. What are part- files in Hadoop & 6 ways to merge them
10: Solving AlreadyBeingCreatedException & LeaseExpiredException thrown from your Spark jobs
09: Running a Spark job on YARN cluster in Cloudera
08: Learn Spark how to convert RDD in Java to Dataframe with examples
07: Learn Spark Dataframes to do ETL in Java with examples
06: Learn how to access Hive from Spark via SparkSQL & Dataframes by example
05: Learn Hive to write to and read from AVRO & Parquet files by examples
04: Learn how to connect to HBase from Spark using Java API
03: Learn Spark & Parquet Write & Read in Java by example
02: Learn Spark & AVRO Write & Read in Java by example
01: Learn Hadoop API by examples in Java
BDT - Map Reduce
MapReduce to HBase: Read from & write to
2. Hadoop MapReduce Basic Tutorial
1. Hadoop MapReduce Basic Tutorial
BDT - Spark and Scala
02: Spark RDD grouping with groupBy & cogroup in Scala tutorial
01: Spark RDD joins in Scala tutorial
BDT - Spark & Java
12: Spark streaming with “fileStream” and "PortableDataStream" simple tutorial
11: Spark streaming with "textFileStream" simple tutorial
05a: Spark DataFrame simple tutorial
10: Spark RDDs to HBase & HBase to Spark RDDs
09: Append to AVRO from Spark with distributed Zookeeper locking using Apache's Curator framework
08: Spark writing RDDs to multiple text files & HAR to solve small files issue
07: spark-xml to split & read very large XML files
01B: Spark tutorial – writing to HDFS from Spark using Hadoop API
06: Spark Streaming with Flume Avro Sink Tutorial
05: Spark SQL & CSV with DataFrame Tutorial
04: Running a Simple Spark Job in local & cluster modes
03: Spark tutorial – reading a Sequence File from HDFS
02: Spark tutorial – reading a file from HDFS
01: Spark tutorial- writing a file from a local file system to HDFS
BDT - PySpark on Databricks
Q08- Q12 Scenarios Based Hive Query Language (i.e. HQL) Interview Q&As
22: Writing Tests in Databricks Notebooks in Python
04b: Databricks – Spark SCD Type 2 with Merge
04a: Databricks – Spark SCD Type 1 with Merge
11A: Databricks – Spark ML – Pandas Dataframe & Matplotlib
21: Databricks – Spark ML Naive Bayes
20: Databricks – Spark ML K-Means
19: Databricks – Spark ML Random Forrest Classifier
18: Databricks – Spark ML Decision Tree Classifier
17: Databricks – Spark ML K-Folds Cross Validation
16: Databricks – Spark ML Multiclass Logistic Regression & Pipeline
15: Databricks – Spark ML – Classification with Logistic Regression
13: Databricks – Spark ML – Dummy Variables
12: Databricks – Spark ML – Categorical Features
14: Databricks – Spark ML – StringIndexer & OneHotEncoder
11: Databricks – Spark ML – Multivariate Linear Regression
10: Databricks - Spark ML - Linear Regression
09: Databricks - Spark Problem 2
08: Databricks – Spark problem 1
07: Databricks – groupBy, collect_list & explode
06: Databricks – Spark Window functions
05: Databricks - Spark UDFs
04: Databricks - Spark SCD Type 2
03: Databricks - Spark SCD Type 1
02: Databricks - Spark schemas, casting & PySpark API
01: Databricks getting started - Spark, Shell, SQL
BDT - Zookeeper
01: Getting started with Zookeeper tutorial
80+ Python FAQs
22: Python Duck typing tutorial
21: Python function overriding tutorial
20: Python function overloading tutorial
19: Python operator overloading tutorial
17: Python OOP and @property decorator tutorial
18: Python Abstract Base Classes (i.e. ABC) tutorial
16: Python multithreading producer/consumer & semaphores tutorial
14: Python Closures, Partial functions and Currying tutorial
13: Python working with files tutorial
12: Python enumerate vs zip tutorial
15: Python multithreading tutorial
11: Python *args and **kwargs tutorial
10: Python working with collections tutorial
09: Python working with String tutorial
08: Python Data modelling tutorial
07: Python dictionary tutorial
06: Object introspection in Python tutorial
05: Python debugging tutorial
04: In Python functions are objects tutorial
03: Python context manager tutorial
02: Python comprehensions tutorial
01: Python Iterators, Generators & Decorators Tutorial

Java Interview Q&As

300+ Core Java Interview Q&As
Core Java - Overview
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Core Java - Constructors
Core Java - Reserved Key Words
Core Java - Classes
Core Java - Objects
Core Java - OOP
Core Java - GC
Core Java - Generics
Core Java - FP
Core Java - OOP to FP
Core Java - I/O
Core Java - Multithreading
Core Java - Data Structures
Core Java - Annotations
Core Java - AOP
Core Java - Other
Core Java - Collection API
Core Java - Differences X & Y
Core Java - Event Driven
Core Java - Exceptions
Core Java - Java 7
Core Java - Java 8
Core Java - JVM
Core Java - Reactive Program
Core Java - Swing & AWT
Core Java - Understanding
300+ JEE Interview Q&As
JEE - Overview
JEE - Web basics
JEE - Web Services
JEE - JPA
JEE - JTA
JEE - API Design
JEE - JDBC
JEE - Microservices
JEE - JMS
JEE - JMX
JEE - JNDI and LDAP
JEE - JSF
JEE - Other
80+ Spring & Hibernate Q&As
Frameworks - Hibernate Q&As
Frameworks - Spring Core
Frameworks - Spring MVC
Frameworks - Spring Cloud
Frameworks - Spring boot
Frameworks - Spring IO
Frameworks - Spring Config
80+ Companion Technologies
Companion - Angular JS
Companion - Domain Knowledge
Companion - FIX
Companion - Git & SVN
Companion - Groovy
Companion - JavaScript
Companion - JMeter
Companion - Maven
Companion - NoSQL
Companion - Regex
Companion - SQL
Companion - Unix
Companion - JSON
Companion - XML
Companion - XSD
Companion - YAML
Tutorials Java, JEE, Spring
Tutorials - ⏯ Starting with Java
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Tutorials - Akka Java
Tutorials - AWS EC2
Tutorials - CI/CD Jenkins
Tutorials - Core Java
Tutorials - Debugging
Tutorials - Java 8
Tutorials - JSON and Java
Tutorials - Java Beginner
Tutorials - XML and Java
Tutorials - CSV and Java
Tutorials - Docker
Tutorials - JEE
Tutorials - Web & Web Services
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Tutorials - Spring & Hibernate
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Tutorials - Spring batch
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Tutorials - Productivity Tools
Tutorials - Kubernetes
Tutorials - ⏯ Videos
Tutorials - ⏯ Starting with Java
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Tutorials - ⏯ JDBC, Hibernate
Tutorials - ⏯ Spring Boot
Tutorials - ⏯ Angular with Spring
Tutorials - ⏯ Q&As
Tutorials - Other
Tutorials - SQL
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Tutorials - Orika Mapping
Tutorials - Pentaho Kettle ETL
Tutorials - Unix
Tutorials - Webspeher MQ
Tutorials - YAML
150+ Coding Q&As ✍
Coding - Can you write code?
Coding - Complete the code
Coding - Converting from A to B
Coding - Designing your classes
Coding - Data Structures
Coding - Arrays
Coding - Big O notation
Coding - Graph Structure
Coding - LinkedList Structure
Coding - Map Structure
Coding - Pointer Algorithms
Coding - Queue Structure
Coding - Searching Algo
Coding - Sorting Algo
Coding - Stack Structure
Coding - Tree structure
Coding - Data Which & Why
Coding - Passing the unit tests
Coding - What is wrong?
Coding - Home Assignments
Coding - Written Test Core Java
Coding - Written Test JEE
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