Ship a Micro-SaaS in a Weekend: Influencer Vetting Tool (Full Stack)

I keep seeing "build a SaaS in a weekend" posts that end with a login page and a Stripe checkout. Cool. What about the actual product? Here's a real one. An influencer vetting tool that agencies and brands actually pay for. The whole thing — frontend, backend, Stripe, the works — in under 400 lines of meaningful code. The Product A simple tool: paste a creator's Instagram or TikTok handle, get a one-page report that tells you if this creator is worth partnering with. The report shows: Real engagement rate (calculated from actual posts, not estimated) Audience quality signals (fake follower indicators) Posting consistency Growth trajectory A simple Go / Caution / Avoid recommendation Free tier: 3 reports/month. Paid: $19/month for unlimited. Why This Makes Money Agencies vet 50-100 creators per campaign. They currently do it manually — checking profiles, calculating engagement rates in spreadsheets, gut-feeling whether followers look real. Charge $19/month. Get 100 agencies. That's $1,9