Senior Full-Stack Developer — Contract (Launch Support)

Senior Full-Stack Developer — Contract (Launch Support)

Type: Contract / part-time (20-30 hrs, with option to extend)

Stack: Next.js 14, Python FastAPI, Supabase (Postgres + pgvector), BullMQ/Redis, LangChain, Clerk, Stripe

About the project

READY™ Clarity is a B2B SaaS platform that diagnoses why websites don't convert — it crawls a site, extracts 100+ signals across five dimensions, runs parallel AI reasoning chains via Claude, and produces a Decision Velocity Index (DVI) score in a six-tab report. The product is largely built (crawler, AI chains, Supabase schema, Next.js frontend, auth, billing) and close to a beta launch.

Scope of work

Code audit: review the existing FastAPI backend, LangChain chains, and Supabase schema for correctness — confirm import paths, table/column names, and data flow actually match what's documented

Close two known gaps

Finish/verify the FastAPI route that runs the signal scan, persists results to Supabase, and triggers the AI reasoning chains

Confirm the 5 LangChain LCEL chains (one per scoring dimension) + aggregator are complete and wired correctly

Deployment support: pair through Supabase migrations, Clerk/Stripe/OAuth setup, Vercel + Railway deploy, and end-to-end smoke testing

Production hardening: error handling, retry logic on the job queue, basic monitoring/logging

On-call for launch week: available for a few days after go-live to fix issues with real users in the system

Must-have experience

Production experience with Next.js (App Router) + TypeScript

Python FastAPI, comfortable reading async code

Supabase or Postgres with Row Level Security

Redis-backed job queues (BullMQ, Celery, or similar)

Has shipped and debugged a real production app solo or on a small team — not just tutorials

Nice-to-have

LangChain / LLM application experience

Experience with Clerk, Stripe, or OAuth integrations (Google, HubSpot)

Comfortable working from existing architecture docs rather than starting from scratch

How to apply

Send a short note on

A production app you've shipped with a similar stack (link if public)

Your day rate or hourly rate

Your availability in the next 1-2 weeks

We'll do a paid 1-hour code walkthrough as a trial before committing to the full scope.