Rationale
Let’s face it. A developer is expected to know A LOT these days.

A typical job requirement (screenshot)
And that makes interviewing a candidate hard because there is never enough time to ask all the necessary questions.
On the other hand, that also makes preparing for an interview hard because there are too many areas and details to prepare for.
These are in fact the very challenges I faced every time I apply for a new job, or interview to hire a new team member. My solution is to pick 5 essential questions to ask or to prepare.
Below is the list of topics and questions I have researched and compiled in recent years. I provide each question with a rationale for why I considered it essential and a sample answer.
I hope they help you as they have helped me.
Javascript
Five Minimum Viable Javascript Interview Questions
Five Minimum Viable TypeScript Interview Questions: planned
Five Minimum Viable ReactJs Interview Questions: planned
Java
Five Minimum Viable Spring REST Interview Questions
Five Minimum Viable Spring IoC Interview Questions
Five Minimum Viable Spring Data Interview Questions: planned
Five Minimum Viable Spring Security Interview Questions: planned