Build fundamentals
Solve coding tasks in 14 languages with executable tests and immediate feedback.
For developers
Practice the work behind modern engineering interviews.
One workspace for coding, SQL, prompting, AI critique, and verification. Pick a mode, do the work, understand the result, and improve.
Work with data
Practice SQL and data reasoning without choosing a rigid job-title path.
Direct and critique AI
Write better prompts, identify flawed output, and explain what you would trust.
Verify before shipping
Use tests, failure modes, and decision notes to turn confidence into evidence.
Public practice, clear boundaries
Practice builds transferable skills. Employer assessments are configured separately around each company's work and do not expose private question lists.
- Free practice with saved progress
- Coding, SQL, and AI-era modes
- Executable tests and custom verification
- Employer interviews stay separate