Full Stack Engineer Multi Sas platform Part Time

Full-Stack Engineer — Multi-Tenant SaaS Platform (Part-Time Contract) We're looking for a full-stack engineer to join an existing, live, revenue-generating SaaS platform serving multiple organizations, each running their own events with their own staff, participants, and payments. The product A multi-tenant event management platform covering the full lifecycle — setup and configuration, participant registration and checkout, live operational tooling for staff running an event in real time, results/reporting, staffing and permissions, and payments. Two live environments (production and a demo/sales environment), each its own deployment and database, built from a shared codebase. The stack Server-rendered-by-hand HTML/CSS/vanilla JS on the frontend — large, purpose-built single-file views per screen rather than a component framework Serverless API functions (Vercel), dispatch-by-resource pattern to work within platform function-count limits Postgres via Drizzle ORM (Neon) Clerk for auth — two separate identity systems (internal staff/org accounts vs. end-user/customer accounts) Stripe for payments (currently test-mode) Blob storage for uploaded files/documents Transactional email via Resend Who the product serves Multiple distinct roles per organization — an admin/owner role with full configuration access, several operational staff roles with scoped real-time permissions, an end-customer-facing role for registration/checkout, and a platform-level super-admin role. Each role has its own dedicated view. What's real vs. not This isn't a prototype — auth, payments, scoring/operations, and email are wired to a real backend with real users. But it grew fast through iterative buildout, so expect inconsistencies: some features assume data shapes that don't match how the business actually works, some UI exists without full backend support, and configuration for the same concept sometimes lives in more than one place. Reading the authorization/permissions model first is the fastest way to get oriented. What we need Someone comfortable working in an existing, imperfect, live system — tracing a bug or a data-model mismatch across frontend, API, and schema, understanding that a schema change here means a real production migration against real customer data, and making judgment calls about when to fix root causes vs. patch symptoms. Nice to have (not required) Multi-tenant SaaS architecture experience — data isolation between organizations, per-tenant configuration Familiarity with Drizzle ORM or similar lightweight TypeScript/JS ORMs (Prisma, Kysely) Payments infrastructure experience beyond "call the API" — webhooks, idempotency, reconciling expected vs. actual state Experience with a live-operations product component — something people use in real time, not just CRUD at rest Comfortable in a large, hand-built, framework-free codebase Vercel (or similar serverless/edge platform) experience, including working within real platform limits Basic transactional email infrastructure experience (Resend, SendGrid, Postmark) Has personally written and run a production database migration, and understands why that carries more risk than a feature branch Engagement Part-time contract, ~15–20 hrs/week to start.