Interview prep
Coding interview prep that grades your code — and your Big-O
Three levels per language: L1 for your first interview, L2 for working engineers, L3 for FAANG coding rounds. Every question runs in your browser against visible and hidden tests, has a Complexity Lab that measures your solution as the input grows, and an AI coach that helps without handing you the answer.
Choose a language
- Python156 questionsL1 fundamentals, the 95-question L2 working-engineer sheet, and L3 FAANG patterns — with the Complexity Lab and Solvi.Open the roadmap →
- JavaScriptSoonThe same three-level format for JavaScript is in preparation.
- TypeScriptSoonThe same three-level format for TypeScript is in preparation.
- JavaSoonThe same three-level format for Java is in preparation.
- C++SoonThe same three-level format for C++ is in preparation.
- C#SoonThe same three-level format for C# is in preparation.
- GoSoonThe same three-level format for Go is in preparation.
- RustSoonThe same three-level format for Rust is in preparation.
- KotlinSoonThe same three-level format for Kotlin is in preparation.
- ScalaSoonThe same three-level format for Scala is in preparation.
- PHPSoonThe same three-level format for PHP is in preparation.
What every question includes
Input → expected output
Visible examples and hidden edge cases, with your output, prints and timing for every test.
Time and space complexity
Commit to a Big-O, then measure your code against the optimal and brute-force solutions.
Solvi, the AI coach
Explains, hints, debugs and plays interviewer — it sees your code, not just the question.