https://leetsys.dev

I built a free platform for practicing system design interviews!: https://leetsys.dev. The currently available problems will always be listed as free!

It lets you chat with an interviewer in real time as you work through a system design problem. It also gives you detailed feedback at the end of the interview that you can use to assess your performance and see where you can improve. Please try it out and let me know what you think!