Coffee Chat with Karun

I had a chat with Karun, he's offering free 1:1s on Topmate.

Here are some notes:

Why MS > PhD

  • didn't have research experience


  • narrowed down DS programs, CMU, Stanford and Columbia

experience at amazon

  • ships fast
  • 6 weeks sprints
  • documentation heavy, makes you more replaceable
  • uses notebooks in DS team, python files in Applied Science team
  • PiP culture
  • shipping things on AWS is seamless

experience at walmart

  • in e-commerce team, recommender systems, trying out LLMs
  • behaves like a startup, mostly GCP
  • issues with data, infra, etc.


  • when you become SME, SWE isn't as fast-paced, do the same things, DS has something new every day
  • SWE ships features a lot more, DS shipping model has a lot more failure rate, offline evaluation and metrics don't translate to online


  • Coding (leetcode easy, medium)
  • SQL
  • Stats (A/B testing, hypothesis testing, p-values)
  • ML (basics, assumptions, when to use, metrics)
  • Deep Learning (based on what's on your resume and role)
  • system design (case study)


  • good at reading research
  • StackOverflow better than ChatGPT

It was great talking to a senior DS currently working in the industry.

Having access to mentors like this is really valuable.

I look forward to more sessions with him and other professionals on topmate.