Output is no longer signal. InterviewSignal captures the full candidate work trail — every prompt, tool call, diff, and git commit — and grades how they think, not what they submit.
01
Write a problem, define a rubric, set a time limit. Get back a code like INT-4829-XK. Share it with 5 candidates or 500.
02
One pip install. Candidate works in their own IDE with their own AI tools — Claude Code, Codex, Gemini, Cursor. No sandbox, no browser IDE.
03
Every prompt, tool call, file change, and git commit is logged in a tamper-evident hash chain. The session knows who drove the thinking.
04
Auto-graded against the rubric on submit. HM reviews ranked submissions in the dashboard. 200 candidates in 15 minutes.
🔗
Every prompt, tool call, and file write is chained. Any tampering breaks the chain. Gaps in the log are their own red flag.
🤖
Graded on how they used AI — not whether they used it. High-leverage use scores well. Paste-and-accept scores poorly.
📂
Every candidate prompt silently creates a git commit. You see the code evolve step by step, not just the final diff.
🚩
Too fast, too few interactions, uniform timing, hooks gap, diff mismatch, prompt ratio — all surfaced automatically.
⚡
pip install, one command, done. Works in Claude Code, Codex, Gemini CLI, Cursor, and Aider.
🔒
Community relay on Vercel + Supabase by default. Self-host on Fly.io for full isolation. No telemetry, no tracking.
They validate the category. The default shouldn't be another locked-in SaaS.
| Saffron (YC) | OpenRound | InterviewSignal | |
|---|---|---|---|
| Model | Managed SaaS | Managed SaaS | Open-source infrastructure |
| Environment | Browser IDE sandbox | Hosted browser + CLI | Candidate's own IDE |
| AI tools | Platform-controlled | Platform-controlled | Any — Claude Code, Codex, Gemini, Cursor |
| Code evolution | Session replay | Submission trace | Per-prompt git commits |
| Tamper evidence | Session replay (vendor) | Not stated | Hash-chained + 9 automated flags |
| Assessment quota | 5–15/mo + $49 extra | 5–20/mo + custom | Unlimited |
| Pricing | From $199/mo | From $149/mo | Free forever |
| Interview data | Vendor servers | Vendor servers | Your servers |
| Self-hosted | No | No | Yes |
| Open source | No | No | Yes |
| Trust model | Vendor-verified | Vendor-verified | Cryptographically verifiable |
Backend, MLE, frontend — real engineering problems with rubrics you can copy directly into the dashboard.
Browse problems →No platform lock-in. No setup call. No assessment quota. Free forever.