Blog Archives

01: 30+ Java architect interview questions & answers – Part 1

One of the very frequently asked open-ended interview questions for anyone experienced is: Can you describe the high-level architecture of a recent application you had worked on? You can be asked:

1) to draw an architectural diagram on a white board and
2) to provide a brief description of the architecture, and
3) to elaborate on decisions, technologies & frameworks used, alternatives considered, pros, cons, challenges, risks, etc ….

Java Application integration styles

Q1. What are the different application integration styles?
A1. Enterprise systems don’t stand-alone. They integrate with many other corporate systems to provide mission critical services to the clients. There are a number of different integration styles like

#1 Shared database

where multiple applications share the same database. This approach is simple, but has disadvantages such as

1) More likely to hit performance & bottlenecks and scalability issues. SQL Databases don’t really scale.

2) Any adjustments (e.g. version upgrade) to the database for one application will have side effects on other applications. Complicates indexing and table partitioning as different applications have different needs.

3) Concurrency & timing issues as there could be chronological dependencies among processes that share the database. What about different applications working on the same tables concurrently? What if one application modifies the data that should have been altered by another application first?

#2 Batch file transfers

Applications will have their own databases, and the data from one application will be copied into another application’s database via an over-night or regular interval batch jobs with an ETL (i.e.… Read more ...


02: 30+ Java architect interview questions & answers – Part 2

This extends Q01: 7+ Java Architectural Patterns Interview Q&As – Part 1. Q2. How does a Java EE application integrate with other systems? A2. Using various protocols like HTTP(S), WebSocket, SOAP, AMQP, RMI, SFTP, TCP, SSH, FIX, proprietary protocols, etc: Note: OSI (i.e. Open Systems Interconnection) is a conceptual model…

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03: 30+ Java architect interview questions & answers – Part 3

Continuation of Java architecture interview Q&As – part 1 & 7+ Java architectural patterns interview Q&As – Part 2. Q3. Can you discuss some of the high level architectures you are experienced with? A3. Be prepared for a white board session on architectures, especially the bird’s eye view of the…

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03: How would you go about designing an online shopping cart?

This question is a very popular white board session question for both Java architects and experienced JEE Developers. You need to draw on your experience to tackle this question as there are no right or wrong answers. These high level diagrams and summary will help you refresh your memory. Q….

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04: How to go about designing a medium size JEE app?

A very popular open-ended question to judge your Java/JEE experience. Q. How would you go about designing a medium sized JEE application? A. Don’t start with 3-tier architecture, logical layers, Spring/Hibernate framework etc. The phases of designing any systems are: Requirements Gathering => Baseline Architecture => Design Alternatives & impact…

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