• (1) Before I interviewed, I spent 2 days to solve 50 leetcode problems, focusing on linked list, trees using pointers (things that are not in CP). Interview questions are really easy. Most difficult part are asking the right "clarification questions" and finding the most simple algorithm so that your interviewer understands what you are doing (e.g. don't use segment tree, rolling hash).

• (4) Generally you need ~3 years of experience to apply for L4 (shorter if you worked at other big companies before). And you have to explicitly tell recruiters that you only want to apply for L4.

• (6) I actually want to ask about interviewing.io. Do they have (trained) interviewers from FANG? How do they give you feedback?

Glad you liked it, thanks for reading! My answers:

1. Yes, it may have been an overkill a bit, but I didn't want to leave anything to chance. I didn't really learn any new algos from Leetcode, and I think that even if I didn't solve any problems there (or just ~50), I would have a fair chance of passing interviews anyways. On the other hand, at the time of interview preparation I hadn't solved CP problems for a long time, and was a bit rusty at problem solving in general. So I looked at leetcode as a way to get back in shape (including speed), learn interview specific techniques, and practice solving problems in Java (which is my first choice for interviews and work, but not CP).
2. I think I partially answered it in 1, and the answer if very probable yes. If looked at as probability, with half the time my chances of passing all onsites could have been like 75%, with all the time it was like 90% (very crude estimate). Also, I spent a lot of time reading material for system design (this also helps to be a better engineer in general) and behaviour interviews, so there's that.
3. I passed phone interviews with 7-8 companies (failed one :), but chose to go only to 4 onsites. Got 4 offers.
4. It's hard to remember exactly, I am not sure if positions I applied to had levels attached to them (some range may have been implied). I got L4 or similar level offers in the end.
5. Ha, I think I wanted to check some small PHP related part in "Learning PHP, MySQL & JavaScript" (i.e. how is it actually suggested to do in textbooks?), but ended up unexpectedly enjoying several chapters. Not really necessary if you know web based stuff, but much better than I expected :) "Modern Operating Systems" is a great book, and I read some chapters regarding hardware and memory management (paging, caching, virtual memory, etc) there. Great stuff.
6. Not sure why, but I think when I prepared interviewing.io was somehow different than how it is now. If it is really what it promises to be now, then I would say use it.

I never heard of "Elements of Programming Interviews" before. CTCI is a classic on the other hand

Geeks for geeks solve NP problems in $$$O(nlog(n))$$$...

Funny, because just yesterday I was looking into if it's possible to forever exclude GeeksforGeeks from my google search results (^▽^;)

There may be some good articles there, but the average quality is very low. Also, they have articles just about everything, and pollute google search results...

Projects can be beneficial for two reasons: 1) they may make your CV look better, especially if the project is successful or you don't have much experience 2) working on a project can increase your software engineering skills, which increases your chances of getting hired.

Also I would say people who like software engineering tend to start projects, and tend to be better software engineers, so there is some correlation.

But in general, projects don't matter much in hiring decisions :)

1. I would say know your fundamentals well. Stuff like networks, databases, general web stuff. Most of it should be covered with good university courses.
2. No, there are no requirements for any frameworks or any particular tech. At the same time, I would say some work experience or personal projects definitely help (you simply become a better dev with them), and you will probably learn some frameworks there anyway.