I Built a JavaScript Interview Prep Platform with Interactive Code Visualizations

If you've ever bombed a JavaScript interview because you understood a concept but couldn't explain it clearly — this post is for you. I've been building jsinterview.dev — a free JavaScript interview prep platform that teaches you concepts through interactive step-by-step code visualizations . Think of it as Python Tutor, but purpose-built for JS interviews. The Problem I Was Solving Most JS learning resources fall into one of two camps: Read-heavy docs — great for reference, terrible for building intuition LeetCode-style grinders — great for algorithms, but skip the JS internals entirely When I started prepping for frontend interviews, I kept hitting the same wall. I knew what a closure was. I could recite the definition. But when an interviewer asked me to walk through how the call stack and heap memory behave when a closure forms — I froze. The missing piece? Visual, step-by-step execution . What jsinterview.dev Offers The platform is structured around 4 phases that mirror how real i