For Paytm Noida location
Round 1:(Machine Coding Round)
This round was a machine coding round and some MCQ’s based questions were also asked(1 hr)
This round was taken on the mettl platform.
- MCQ’s based were basically asked on Vanilla Javascript and frameworks like AngularJS and React. There were around 20-25 questions combined on these.(level – medium).
- Machine coding section comprises of building a chess like game using HTML, Plain CSS(not any preprocessor like Sass or less) and Vanilla JS(not frameworks) but not same complexity as we play real chess. This round was a great mess and frustrating as the browser version on which I have to write code was IE6- IE7. Every css property we used nowadays like flexbox, grid, box-sizing etc not worked on this. Great relieve for me was that I can use google for searching. After so excruciating pain on searching for around 45 min, I’m able to build game but it didn’t comprises of all features they have asked in the question. But it was about near to completion.
Above all this the laptop they have given to me for coding was so laggy i can’t explain in words.
Round 2:Face to face(1.5HR)
This round interviewer was very humble.
- Tell me about yourself. :p Mandatory question
- He started with my project discussions, asked me to explain any project, and deep discussion on that project.
- He asked questions on JS concepts like hoisting, Promises, async/await, Closures, Prototypes, Prototypal inheritance.
- After these concepts he gave me one question – sum(1)(2)(3)(4)……..(n) which uses the concept of closures and recursion.
- He also asked about functional programming, PWA concepts like service and web workers, indexedDB, Websql, Client side storage techniques, their usage i.e. when to use what and differences b/w them.
- Debouncing and Throttling code was also asked.
- Also some DS questions were also asked like Find loop in linked list, given a string of parentheses – find the string which is balanced or not or some basic questions on trees like lca, left, right, top and bottom view of binary tree.
Round 3:Face to face(45mins)
This round interviewer was very knowledgeable and calm.
- Tell me about yourself. :p Mandatory question
- One algo question was asked which uses some core Js concepts like prototypes and the JS methods which i used here then he asked me to right there polyfills. We start from O(n^2) time complexity and then with subsequent discussions reach to O(n).
- He asked about what are closures and what are there practical usages in real life. One question was asked on this was write a function using which i can perform two operations ie getting the latest count and also using that function to increment the count.
- then he asked an output question which uses string immutability concept in JS.
Round 4:Face to face(40mins)(Hiring Manager Round)
- Tell me about yourself. :p Mandatory question
- He started with my project discussions, asked me to explain any project, and deep discussion on that project.
- Asked me about JS design patterns i have used and implemented. For every design pattern i named he asked me to write working code for it.
- Write a code to reverse a linked list.
- Modified the above question to reverse the linked in given k group size.
- Asked me about directives. digest cycle, dependency injection in angular.
- Diff b/w $apply and $digest.
- What is http2 and diff b/w its previous version i.e. http1.1.
- PWA and its concepts.
Verdict – Selected.
I would suggest you to discuss your approach with the interviewer because they are basically looking for how you approach a problem and how to come up with an answer i.e. your thought process while formulating the solution to the problem.