How to practice coding interviews with AI for free

The fastest way to get better at coding interviews is deliberate practice with quick feedback. An AI copilot gives you that feedback in seconds, for free. The trick is to use it as a coach, not as a crutch.

The routine: 45 minutes a day

1. Solve it yourself first (20 min). Pick one problem on LeetCode or HackerRank. Talk through your approach out loud, as you would with an interviewer.
2. Compare with the AI (5 min). Press Ctrl+Shift+Space in AI Interview Helper to get a reference solution. Compare the approach, complexity and edge cases with yours.
3. Drill the follow-ups (10 min). Interviewers rarely stop at the first solution. Ask the AI: "What follow-up questions would an interviewer ask here?" Answer them out loud before reading its version.
4. Explain it back (5 min). Explain the final solution in your own words. If you can't, you don't own it yet.
5. Log it (5 min). Write down the pattern (two pointers, sliding window, BFS…) and the mistake you made. Review the log weekly.

Practice the spoken part too

Most interview loops include behavioral and system design rounds, where how you speak matters as much as what you know.

• Paste your resume into the app settings so answers use your real projects.
• Turn on listening (Ctrl+Shift+L), play a recorded question such as "Tell me about a time you disagreed with your manager", and compare the suggested STAR answer with yours.
• For system design, ask for a structure (requirements → API → data model → scaling) and practice filling it in yourself.

Useful prompts

• "Give me a hint, not the solution." Great when you're stuck but still want to solve it yourself.
• "Review my solution for bugs and edge cases." Paste your code into the chat.
• "Explain the time and space complexity step by step."
• "Rewrite this in Java / Go / C++." Useful when the interview language differs from your daily one.

Which model to use for practice

For algorithm problems, a strong reasoning model gives the best explanations: Claude Opus or GPT-OSS 120B on Groq. For quick drills, Groq's GPT-OSS 20B answers almost instantly. For screenshots, use a vision model such as Gemini Flash. The setup guide has a full comparison.

Common mistakes

• Reading the answer first. You learn recognition, not recall. Always attempt the problem first.
• Practicing silently. Real interviews are spoken. Narrate your thinking every time.
• Grinding random problems. Group practice by pattern, and move on once a pattern feels easy.