British Telecom Interview Experience | Set 1 (1+ years experienced)

First Round (written)

There were multiple choice questions on Aptitude and Java. Three marks for correct answer and -1 for wrong answers.

1. Aptitude questions were lengthy and tough. But the cutoff will be less.

2. Java questions were comparatively easy. A lot of questions were from multi-threading.

Second Round (Technical interview)

1. What is object immutability? How to create immutable objects in Java? Uses of immutable objects.

2. Difference between synchronous and asynchronous communication? Explain asynchronous communication protocols. (Like message queues)

3. Write a fully functional thread-safe singleton design pattern. How can we break the singleton property?

4. Given a m*n grid like a chess board. Derive a formulae for the number of squares in it.

Third Round (HR interview)
Discussed my current pay and expected number.