For the first time in my life - i dare to interview the interviewer

Recently I went to some job interview, which i, lets face the truth - totally failed. Since my career as developer last longer than 10 years, and had chance to work in a lot of places and on a lot of projects - it is definitely not my first interview, and event not first failed interview. Yet, at this post I want to tell you about some unique experiences I had during this particular adventure.

Details

Lets start from the beginning: It was an interview for the front-end position, and i was asked some javascript questions, like: how to check if a variable is an Array, or: how to prevent click event from bubbling from a child element to its parent. To be honest - I found myself caught unprepared for those questions (since almost year im working as a devops and completely forgot the differences between currentTarget and target, e.preventDefault and e.stopPropagation - shame on me!).
Yet the interesting thing was, that at some point, instead of focusing on my loose situation - I found myself trying to analyze the situation of the team that seeking to hire some frontend developer - and how it would be feel like working at this team

Conclusions

Here are some conclusions I come up with:

• The interviewer didnt knew about ES Array.isArray method (instead - the answer he considered right was

  
  variableToCheck.constructor === Array
  
  

  )
• Interviewer was surprised to find about existence of native javascript "fetch" method - instead he preferred to use jQuery ajax method for doing ajax request
• The question about stopPropagation was a part of question:
  "how do you prevent a click on some element inside modal window to propagate to an overlay, when implementing modal dialog"
  - i tried to point out that nowadays browsers come up with a dialog HTML5 element which do exactly the dialog scenario (without need of coding anything) - but again caught the interviewer by surprise

Summary

Things can have various - a negative and a positive angles. At least I finally find out that as much important as to prepare yourself well for an interview - It is also important to try and figure out: what kind of work need to be done in the place you apply for. For example - this place did the impression of building some kind of new javascript framework instead of using some current, much better and simplier existing tools - a work I for sure would not be comfortable doing...