Aphonso Interview Experience

I applied via angelist. I was asked to write code on collabedit while we were discussing problems over phone. Interviewer jumped straight to Technical questions, no Tell me about yourself.

Q1. Write a program to calculate power(x, n) in your favorite programming language.
Ans: I divided the problems in subproblems of size(y/2) and called the subproblems recursively. He then asked me to further optimize it. I tried memoization and dp, he then said there is no need of memoization here as one subproblem will be solved only once.

Q2. I used hashmap during the above question, then he asked me about hashmap its internal implementation, insertion complexity etc.

Q3. How are collisions prevented in hashmap, what is hash function etc.

Q4. You are given a binary tree, print level order traversal in zigzag form.
Ans: I did this by first printing level order then reversing where required. I was only required to write pseudo code. I was not able to explain him the recursion.

Q5. Asked Javascript- asynchronous programming, eventloops in NodeJS, asked me the output of following JS program:-
for(var i=0;i<10;i++)
setTimeout(console.log(i), 10);
What would happen if setTimeout is replaced with setTimeInterval?
What would happen if var i=0 is replaced with let i=0 (Ans: It would produce error)
What are closures in JavaScript?

Q6. What is the difference between SQL and NOSQL databases? Advantages of NOSQL databases like Mongodb? Can we have Relational DB in NOSQL?

Q7. Some general questions like what is MVC, AJAX, HTTP keep alive, difference between git pull and git fetch etc.

Q8. Asked questions from what I had mentioned in Resume like what is k-fold cross validation, AngularJS etc.

I got a mail 15 mins after the call that they don`t have good positions matching my experience and skillset. My interview went well, but I think my lack of JavaScript knowledge and poor net connectivity had negative impact on the interviewer.