Next.js + Convex Developer — SaaS Migration & AI Integration

I have two SaaS products that need to be migrated off a third-party platform onto my own infrastructure, and rebuilt with working AI features. Full support for the migration and AI integration is required. The ideal candidate will have experience in SaaS migration and AI integration, ensuring a seamless transition and effective AI functionality. What needs to be built: Website 1: ∙ Next.js frontend matching provided design spec and landing page ∙ Convex backend with file upload handling ∙ OpenAI Whisper integration for audio/video transcription (.mp4, .mov, .mp3, .wav, .m4a, .webm — up to 500MB) ∙ YouTube/Loom URL audio extraction (replacing broken ytdl-core) ∙ Claude API (claude-sonnet-4-6) for moment scoring — working prototype provided ∙ Stripe subscription payments ($0 / $49 / $149 plans) ∙ Free plan gating (3 clips visible, rest locked) ∙ Full results dashboard — clips, social posts, email ideas Website 2: ∙ Next.js frontend matching provided design spec ∙ Convex backend with auth and subscription management ∙ Claude API for AI squad chat — 4 personas (Strategist, Skeptic, Hype Person, Executor) ∙ Stripe subscription ($9/mo founding, $19/mo regular) ∙ Post-payment auth sync — critical bug fix ∙ Member dashboard with squad view and weekly check-ins What I’m providing: ∙ Complete rebuild specification documents for both products ∙ Working AI scoring prototype (React/Claude API) ∙ Working squad chat prototype ∙ Full landing pages (HTML) ready to implement ∙ QA test plan for both products ∙ Domains already purchased Tech stack required: ∙ Next.js (React) ∙ Convex (backend + database + auth) ∙ Claude API (Anthropic) ∙ OpenAI Whisper API ∙ Stripe Connect ∙ Vercel (hosting) Important notes: ∙ Must be comfortable with Convex specifically — not just general React/Node ∙ GitHub codebase may be available from previous platform — ability to migrate OR rebuild from scratch required ∙ Canadian founder — Stripe must be set up under Canadian account ∙ Fixed price preferred over hourly