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01: 13 Java low latency interview questions & answers

Have you seen job advertisements requiring Java candidates to work in low latency, high throughput, real-time and distributed systems with share-nothing architectures? Wondering what questions you will be asked? If you are an experienced Java developer targeting high paying skills then it pays to get a good handle on Java low latency interview questions & answers.

You will be quizzed on the low latency application you had recently worked on especially the outcomes in terms of the latencies, response times, and throughput along with the challenges you faced.

Q1. What do you understand by the term latency?…


02: 15 key considerations for low latency Java applications

Extends Writing low latency applications in Java interview Q&As. If the job description says “low latency” application, then be prepared. Even if “low latency” experience is not a requirement, all employers like candidates who can not only build systems that perform well, but also can stress test (e.g. JMeter), profile…


02: 5 Java multithreading scenarios interview Questions & Answers

Java interview questions & answers on multithreading scenarios to judge your experience in building applications with concurrency in mind. Q1. Can you give some scenarios where you built concurrent systems? A1. In a concurrent system different threads run concurrently, whereas in a distributed system different processes often in separate machines…

05: Q19-Q24 How to create a well designed Java application?

A software application is built by coupling various classes, modules, and components. Without coupling, you can’t build a software system. But, the software applications are always subject to changes and enhancements. So, you need to build your applications such a way that they can not only adapt to growing requirements,…

1. Asynchronous processing in Java real life examples – part-1

The scenario based questions are very popular with the job interviewers, and some scenario based questions are related to decoupling and asynchronous (aka non-blocking) processing in Java with message queues/topics, database tables where one process inserts data and another process consumes the inserted data, and Future objects in Java multi-threading….

10 ERD (Entity-Relationship Diagrams) Interview Q&As

Q01. Can you describe a business domain of a Telecom company offering multiple services to its customers? A01. A Telecom company will have entities such as Customer, Account, Subscriptions & Products representing a business domain. 1) Each customer entity has a name, physical address, and an email address. 2) A…


11 “In your Java experience” interview questions & answers

Q1. In your Java experience, what are some of the common dilemmas you face when writing unit tests? A1. Whether to fix the code or the test. When you write unit tests, sometimes you feel compelled to change your code just to facilitate the test. For example, when you need…


12: 5 Java synchronize & concurrency mgmt scenarios interview Q&As

This extends Q1. Can you give some scenarios where you had used multi-threading in Java applications? Q2. Can you give some scenarios where you used the synchronized keyword in Java? A2. Firstly, you need to assume that your code is always going to be accessed by multiple threads. Scenario 1:…


15 slacknesses or lack of experience that can come back & bite you in the back

Production issues seek the attention of middle and top level management. Often these are intermittent issues that are harder to reproduce in lower environments without the right know-hows & tools. Some will shrug it off as “Cannot be reproduced“, whilst others will seize the opportunity to showcase their technical strengths & know hows to go places. Here are a few things that you must pay attention as a software developer, designer or architect to prevent any future embarrassments. You can use this as a check list.

#1: Not externalizing configuration values in config file(s) (E.g: .properties, .xml, …

18 Java scenarios based interview Q&As for the experienced – Part 1

Let’s look at scenarios or problem statements & how would you go about handling those scenarios in Java. These scenarios interview questions will judge your Java experience. Full list of Java scenarios based interview questions are covered at Judging your Java experience via scenarios based interview Q&As.

#1. Caching

Q01.Scenario: You need to load stock exchange security codes with price from a database and cache them for performance. The security codes need to be refreshed say every 30 minutes. This cached data needs to be populated and refreshed by a single writer thread and read by several reader …


18 Java scenarios based interview Q&As for the experienced – Part 2

This extends 18 Java scenarios based interview Q&As for the experienced – Part 1 #9 Single Sign-On Q09. Scenario: You have a number of applications like cash, mortgages, investments, etc where a user has to login separately into each system. For example, a user with all 3 products has to…

2. Asynchronous processing in Java real life examples – part-2

Extends: 1. Asynchronous processing in Java real life examples – part-1. Example 3: Trade execution reports are received & processed asynchronously If you are working in an online trading application, you may want the functionality to queue trades and process them when the stock market opens. You also asynchronously receive…

20 Java coding interview questions – tips & considerations

Java coding interview questions are very common in job interviews. Good coding skills are essentials for passing the peer code reviews with flying colours. Here are 17 coding tips with Java examples.

Tip #1: If you are asked to write a function or code, make sure that your code fails fast. Check for pre-conditions and post conditions. For, example, if you are writing a function to “apply given interest rate to given balance”.

Pre-condition: Balance is a positive number and greater than zero. Interest rate is not a percentage and can’t be 1.

Post-condition: new balance …


3 key “How would you go about …” Q&As to judge Java experience

Q1. How would you go about judging the code quality of other developers? A1. 1) Code written with unit tests and progressively re-factored where necessary to make it more maintainable, testable, and readable. 2) Unit tests need to be written properly — mock objects using frameworks like Mockito and Power…


30+ SDLC activities you perform as a Java developer

Don’t get overwhelmed by this activities list. This proves why employers favor experience to just academic qualifications alone. It also emphasizes the fact why good technical skills must be complimented with good soft skills and right attitudes get things done as a software developer. I also vividly remember my first…


6 Key considerations in processing large files in Java

Q1. What are the key considerations in processing large files?
A1. Before jumping into coding, get the requirements.

#1 Trade-offs among CPU, Memory Usage & Disk I/O

Processing a file involves reading from the disk, processing (e.g. parsing an XML and transforming), and writing back to the disk. It is also a trade off in terms of what is more important to you like having better I/O, better CPU usage, and better memory usage. It is important to conduct profiling to monitor CPU usage, memory usage, and I/O efficiency.

1) Reading the data from the disk can be I/O-heavy


7 Java debugging interview questions & answers

Q1. How would you go about debugging thread-safety or concurrency issues? A1. #1: Manually reviewing the code for any obvious thread-safety issues. Good knowledge of multi-threading is required. #2: List all possible causes and add extensive log statements and write test cases to prove or disprove your theories. The log…

8 real life Java scenarios with Situation-Action-Result (i.e. SAR) technique

The SAR (Situation-Action-Result) technique is very useful to tackle open-ended questions like:

1. What were some of the challenges you had encountered, and how did you go about fixing them?
2. What are some of your achievements that you are most proud of?
3. Why do you like software engineering?

and the list goes on. The answers you provide will reveal a lot about your experience & industry knowledge & be prepared for further drill-down questions based on your answers & this helps you steer the interview in the right direction leading to enlightening …

9 Java Garbage Collection interview questions & answers

Java Garbage Collection interview questions & answers to ascertain your depth of Java knowledge in building industry strength Java applications. Determining optimal Garbage Collection (GC) settings is critical to achieve high throughput & low latency. Q1. In which part of memory does Java Garbage Collection (i.e. GC) occur? When does…

Dealing with concurrent modifications in Java

There are scenarios where you need to deal with concurrent modifications in Java. Here are 2 scenarios that I can currently think of. Scenario 1: Looping through a list of items and removing an item in the list could lead to “ConcurrentModificationException”. Here is an example. Code that throws an…

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