Interviewed with illumina in SG. Take home assessment to complete within 3 days. Pick 1 out of 10 topics and build a winform application based on the topic. Very simple.

Got into the next stage of technical interview with 4 senior / staff engineers. I have been to interviews with other companies concurrently and I have to say this is the worst interview I have ever experienced. 3 of the interviewers are extremely rude. Mocking or smirking just because I explained some concepts wrongly. Very unprofessional behavior from engineers of a senior level. Wouldn't want to work with illumina knowing that their engineers have no basic form of respect. Asked them about their projects, doesn't sound exciting either. If you are looking for long term growth, highly recommended not to waste time interviewing with them. HR were genuine, unlike their engineers.

What design patterns have you used

No coding questions, just on your past experiences and OOP concepts