About Cla64.ai
Cla64.ai is a place to practice coding interviews the way engineering work actually happens: on real code, with real tests, and with an AI interviewer that asks why you made each decision.
Why it exists
Most interview practice is algorithm puzzles: an empty function, a clever trick, a pass or fail. But the job - and more and more interviews - is something else. You open code someone else wrote, read a bug report, run the tests, change things carefully, and explain your choices to the people around you. Now that AI tools are part of everyday work, and some companies allow them in interviews, the part that matters most is understanding and defending the code, not typing it.
Cla64.ai is built to practice exactly that. Each interview opens a small, realistic codebase in VS Code in your browser. The AI in the session is both your interviewer, answering questions about the task and asking about your reasoning, and your assistant, helping with syntax, APIs and tools the way a colleague would - with hints, never the solution. When you're done, it asks you a few questions about your work, and you get a written review of how you worked: what went well, what to improve, and how a strong solution would approach it.
What you can practice
- Debugging from a support ticket or an incident report, as in the rate limiter and the load balancer.
- Building on starting code with tests to pass, as in the bus control center.
- Design in code from a blank project, demoed live, as in parking garage billing.
Exercises are available in Python, JavaScript, TypeScript, Java and C++. During the beta every account gets 3 free practice interviews, and companies can use the same exercises to run real candidate interviews.
Who builds it
Cla64.ai is built by Shilo Drot, an experienced software engineer and ex-Meta. Shilo likes building tools that help people do their work better, and started Cla64.ai to make interview practice feel like the job it's meant to predict.
Questions, feedback or ideas are always welcome - get in touch.