After going through technical interviews for small, medium, large companies in the post corona world, I’ve noticed enough differences that I felt I ought to inform my fellow leetcoders. I also wanted to follow up on my last post and provide some tips.

Choose your adventure

I categorize the companies in tech into the following:

1. Small startups. They have less than 50 employees.
2. Medium companies. They just IPOed or are about to IPO.
3. Big companies. Think FAANG et al.

Small startups

• Work on the specific stacks for their business

  • e.g. web: Ruby on Rails or PhP, (almost) never a mix
  • e.g. ML: pytorch or tensorflow
• They will ask you to work on a take home assignment with their specific stack
• They don’t care about fluff. Can you do what they do? That’s all they want to know.

Medium companies

• They quiz you with coding problems like Leetcode easy, but much longer.

• They expect you to read a very long prompt and apply your data structures.

  • They almost never ask candidates to program a data structure from scratch.

• You need to know the common data structures, but with little to no emphasis on algorithm

  • using the language of your choice, be well versed in the language’s following libraries
  • heap
  • priority queue
  • stack
  • queue
  • set
  • hash map
  • array
  • basic string manipulation methods

• The coding problem emphasizes application

  • You need to know basic SWE principles
  • Write classes, not just a global function

• The coding challenge is usually done via an online coding platform, whether proctored or not. Some popular platforms are:

  • coderpad
  • hackerrank pairing
  • hackerrank solo challenges

Big companies

I had relatively less experience with typical FAANG interviews described in popular books such as CTCI. Here’s my takeaway.

• You need to grind Leetcode easy, medium, and hard.

• Brush up on obscure data structures

  • trie
  • set
  • graph
  • linked list
  • tree

• Emphasis on the algorithm part

  • dynamic programming
  • graph, tree traversal
  • recursion
  • backtracking
  • matrix manipulation
  • Tip:
  • Watch youtube tutorials, then proceed to code.
  • Don’t stare at leetcode for hours on end

  • Best Youtube channel I found while deep diving in Leetcode’s comment section

    • https://www.youtube.com/channel/UCmJz2DV1a3yfgrR7GqRtUUA

• Less emphasis on your syntax

  • Caution: this has changed due to remote hiring. See disclaimer/FAQ below.

• System design

  • if you are a new grad, you gotta power through it
  • I personally think it’s not reasonable to test new grads on this. Assuming that new grads had internships during their studies, I can tell you with great confidence that no company would ever let an intern touch production stuff. If they do, they’re in trouble.
  • Watch these youtube channels
  • https://www.youtube.com/channel/UCRPMAqdtSgd0Ipeef7iFsKw
  • https://www.youtube.com/channel/UCZLJf_R2sWyUtXSKiKlyvAw
  • if you don’t have time, here’s a must watch
  • https://www.youtube.com/watch?v=UzLMhqg3_Wc

Disclaimer/FAQ

Is syntax important?

• It’s not supposed to be the point.

• In the past, with whiteboard interviewing, as long as you have retained around 90% of the syntax, it’s a pass

  • e.g. in Python, to test whether a character is a number, is it char.isnumber()? or is it char.isnumeric()? doesn’t matter. You get the gist of it.

• Unfortunately, with remote hiring, it’s no longer the case.

  • Some companies started using interview platforms with built in compilers.
  • The platforms are sometimes not crafted with the flexibility we need.
  • You have to prepare for that. If you can’t beat them, join them. Welcome to the leetcode grind.

Which language do I choose?

Ideally,

• the one you’re familiar with
• the one that’s popular in general

in that order.

Has not knowing a particular programming language backfired?

• Of course, based on my personal experience below.

• Small companies

  • They don’t have the time to onboard you.
  • They don’t care for CS generalists. They need someone here to work with their tech stack ASAP.
  • They usually advertise with a specific tech stack and fully expect candidates knowing their stack.

• Big companies

  • During my interview with one of the As of FAANG, the online coding challenge only allowed C, C++, or Java.
  • I know C and C++, but I used them so long ago that I couldn’t possibly complete 5 coding exercises in 30 minutes.

Conclusion

With remote hiring, it’s more common for companies to automate testing and they care more about your syntactical accuracy. Smaller companies have a different hiring routine. Make sure that you use your time wisely and prepare for the job you want.