Launched an AI tutor that refuses to write code. Bootstrapped, $0 marketing, day 3.

A few days ago I launched CodeTrain publicly (codetrain.ai). The pitch is contrarian to the current agent coding culture: it's an AI coding tutor that will not write code for you. It plans a lesson from your own codebase in tiny steps, you type every line into an editor with a run/test loop, and it grades each step. Beg for the answer and the step gets smaller, not handed to you.

Why I think there's a business here: AI assistants made producing code cheap, and most engineering managers I've talked to have noticed the same side effect. Juniors ship more and understand less. Teams are paying for that gap in review load and bus factor, and not many solutions are available for the countermeasure. Codecademy teaches someone else's codebase. Copilot writes yours for you. The empty quadrant is "learn your own codebase by writing it." A brand new industry with the rising of AI agentic coding.

Where the money is: free browser tier (10 sessions/mo, capped because inference costs real money and I don't want a rug-pull free tier), Pro at $24/mo with repo mode, Team at $32/seat with a ramp dashboard. My bet is the Team tier carries it; individual devs are the funnel and the proof.

Stack is FastAPI on Fly, static site from Cloudflare Pages, auth via Clerk, billing from Stripe, LLM is mainly Anthropic models with BYOK support. (we do have some test models available for usage through OpenRouter as well)

The launch plan is deliberately boring: owned channels this week, Show HN and Product Hunt next week once my accounts have enough history not to look like a bot(not particularly a huge social media fan unfortunately), then a month of Reddit and newsletters. Zero paid anything. I'll report what each channel actually converts.

Question for people who've sold to eng teams: did you land Team plans from self-serve individual users upgrading, or from founder-led outbound? I've budgeted for outbound but I'd love to be wrong.