Senior SaaS Engineer / Technical Lead - PT - Worldwide

Job Posting - Senior SaaS Engineer / Technical Lead — Fractional / Contract — AI-Assisted SaaS Build

Remote · Fractional (part-time, sustained) · Paid pilot engagement first, long-term potential

We're a small founder-led software company building a new multi-tenant SaaS platform for service businesses, including multi-location operators. The product includes compliance-sensitive customer messaging, workflow automation, third-party integrations, AI-assisted functionality, and account/location-based permissions and reporting.

We're building it with a deliberately AI-heavy development model: frontier AI does a large share of the implementation inside a disciplined system — bounded work packages, independent AI review, automated test suites that block merges, and strict rules about what AI may never touch alone. That system needs one experienced production SaaS engineer as its judgment layer. Not to type every line — to own the architecture, review and approve everything high-consequence, and make sure what ships is actually production-grade.

What you'd own:

• Foundation architecture for a greenfield build: managed PostgreSQL with row-level-security tenancy, managed auth, adapter boundaries around providers, CI/CD, staging/production discipline.
• Review and approval of all high-consequence work before merge: schema and every migration, tenant isolation/authorization, auth/session, the messaging consent/eligibility enforcement path, webhook security, deployment and secrets. The tooling routes these to you; nothing merges there without you.
• Reviewing AI-generated code and AI-generated tests with a skeptic's eye, plus sampling the rest.
• Production readiness: backups/restore drills, rollback discipline, observability, maintainability (a stranger should be able to stand the system up from the README).
• Writing down your judgment: short architecture decision records, review notes, and — at the end of the pilot — a written certification of whether this system is fit to continue toward production.

How the engagement works: we start with a bounded paid pilot (roughly 6–10 weeks of fractional involvement — a standing weekly review session plus async reviews within agreed turnaround). The pilot builds the real production-intent foundation (not a throwaway demo) while we test whether this whole working model — founder + AI + you + automated assurance — actually holds up, including planted-defect exercises that test the review system itself (you'll know the program exists; that's the point). If it works and we continue, this becomes a sustained fractional technical-lead role through the build and potentially beyond. We won't ask for a long-term commitment before the pilot earns it — in either direction.

You're probably a fit if you have: senior hands-on experience building and operating a real production multi-tenant SaaS (you owned the data layer and deployments, and you've handled real incidents); PostgreSQL depth — ideally row-level security, or equivalently deep database-level isolation work; disciplined schema/migration habits; server-side authorization design; webhook/API security experience; CI/CD and managed-cloud operations; formal code/test review experience; strong written async communication; and a healthy attitude toward AI-generated code — neither worship nor contempt. Payments (Stripe-class), messaging/telephony (Twilio-class), and prior AI-assisted development are pluses, not requirements. Location doesn't matter; judgment and responsiveness do. No specific degree required.

This role is not: a junior coding job, a ticket-taking role, a bodyshop placement, or a rubber-stamp review gig. If you'd enjoy being the senior engineer who makes an AI-heavy build actually safe to ship — with real authority over the dangerous parts — this is that job.