About

Built by an aspiring PM. Used by one too.

The honest version of why PrepOS exists, what it is, and what it isn't.

The story

PrepOS started as my own interview lab — built across multiple PM loops when generic prep guides and free question dumps stopped earning their keep. I needed a tool that picked the highest-impact next rep instead of dumping a flat 200-question list and asking me to self-prioritise. Nothing on the market did that, so I built it.

I still run the same question bank, the same rubric, and the same adaptive queue before every onsite. The Story principle on the landing page isn't marketing copy — it's literally what I do at 9 PM the night before a loop.

What PrepOS is

  • An adaptive PM interview prep tool calibrated for APM, PM, Senior, Staff, AI PM, and PM-T loops.
  • 250 reviewed PM interview questions across 6 round types.
  • 18 tracked PM concepts mapped to the rounds that test them.
  • Open rubrics — keyword + structure scoring you can read and improve.
  • A real voice-mock simulator with BYO API keys for Anthropic Claude or OpenAI ChatGPT, optional ElevenLabs lifelike voice, and optional D-ID real-video mode.
  • Local-first. Your answers and progress live in your browser.
  • Free to use.

What PrepOS isn't

  • A guarantee of an offer. Practice helps, structure helps, real reps help — but no tool can give you signal you didn't earn.
  • A coaching marketplace. There's no human PM coach behind the scenes. Just a calibrated rubric and a real conversation with an LLM persona.
  • A blackbox. The rubric is in the open, the question bank is in the open, the source is on GitHub.
  • A data harvester. We measure aggregate visits to understand demand, never per-user behaviour. See privacy policy.

What's coming in Pro Pack

Pro Pack is the paid tier — currently in early-access signup. The pitch:

  • AI PM interview question bank (a different round bundle: eval design, hallucination mitigation, cost / latency trade-offs, human-fallback design).
  • Extra question banks beyond the 250 that ship in the free tier.
  • Expert-answer library — full worked solutions to the highest-frequency questions, with rubric annotations.
  • Premium interviewer personas for the voice mock.
  • Optionally: managed API keys (we run the LLM / voice / video so you don't need to BYO).

Drop your email on the landing page or anywhere you see a Pro Pack card to be notified when it launches.

Get in touch

Privacy questions, partnership ideas, found a bug, want to recommend a question for the bank, or just want to say hi — open an issue on GitHub, or reply to any PrepOS email.

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