While looking for programming related jobs, it is common to come across associative terms tied to a particular programming language in the job requirements. So what does it mean to be a proficient JavaScript programmer; or to be familiar with Python? Familiarity with a programming language can be broken up into four categories: Not Familiar, Familiar, Proficient, and Master. While the following definitions are in no way concrete, you can safely use them as a guideline.


  • Know almost every pitfall, gotcha, and best practice. Have a rock solid grasp of the ecosystem.
  • Up-to-date on the language roadmap and philosophy.
  • Have written a substantial amount of source code that others deem high quality.
  • Hard time convincing yourself that you have finally mastered the language.  😉
  • You are part of the community. (hopefully, you give back)
  • Know when to “dumb it down” and exclude advanced usage.
  • Deep understanding of runtime and performance.


  • Know most of the best practices and gotchas.
  • Mostly aware of upcoming language features and philosophy.
  • Most of the syntax is in your head.  If you are rusty, it will take only a couple days to give yourself a refresher.
  • Occasionally look at references but the vast majority of your time is spent solving the real problem at hand.
  • Able to whiteboard in it during interviews. (i.e. fair game if listed in resume)
  • You’ve read and studied a substantial amount of source code that is known to be of high quality.
  • Can identify bad code and smells.
  • Can rattle off at least 5 people in the community whose work you study and respect.
  • Decent knowledge of runtime and performance.


  • You are still hung up on syntax at this stage.  You spend substantial time looking at syntax references instead of solving the real problem at hand.
  • Don’t expect to whiteboard in it during interviews.
  • You can read and mostly understand the source code.
  • You can prepare simple bug fixes or patches.
  • Don’t know much about the ecosystem.
  • You cannot identify bad code and smells.
  • No clue where the community even hangs out.
  • You would be happy if your code compiled or worked at all. Runtime and performance considerations are the least of your concerns.

Not Familiar

  • You need someone to tell you if you qualify as being “familiar”.  😉
  • If someone showed you some source code in the language, you couldn’t even identify what language it is in (or you would have many doubts as to what it might be).

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