Technical interview consist of various questions:
- General front end related questions like http protocol, first page optimization, minification, debugging techniques etc.
- If you are interviewing for a specific framework role make sure you know go through general interview questions for that framework and also be ready to answer how to solve common problems like memory leak or performance optimization with that framework's best practices.
- Practice basic data structures and OOP topics because during the interview you might be asked to design a simple solution for a problem and from the basic solution you might get asked to re-implement it with various data structures (linked list, tree or hashmaps) (syntax doesn't matter much)