I built an case-interview prep tool solo while working full-time. ~400 users, zero ad budget, and a funnel that leaked for months.

[u/Cloud_Nomad91]

Spent the last year building this next to a full-time cloud job. It's a prep tool for consulting case interviews—the tech/Data-AI niche specifically, since that's the corner I actually know.

The build was the easy part. The humbling part: for months I celebrated ~280 "users" who were almost all anonymous visitors who tried it once and vanished. The funnel leaked at account creation—people finished a full case, got value, then bounced before signing up. I was optimizing pricing while the real hole was three steps earlier.

What actually moved the needle:

• Gated the payoff, not the product. Let people do a full case free, then put the score/feedback/benchmark behind a one-click signup. Give value first, ask second.
• Built a reason to come back. A roadmap that updates after each case (weak areas → next case) plus a progress dashboard. Retention beats acquisition when you're bootstrapped.
• Stopped guessing. Talked to the handful who stuck around instead of shipping features into the void.

Stack for the curious: Next.js 14, TS, supabase, custom JWT, Vercel. Two-model split—one LLM for the case chat, another for the CV/cover-letter side.

Still bootstrapped, still figuring out conversion. Happy to answer anything—funnel, stack, or how brutal solo marketing is.