Senior Full-Stack Developer - Saas Backend + Stripe/Twilio/Jobber/HouseCall Pro

Senior Full-Stack Developer — SaaS Backend + Stripe/Jobber/Twilio Integrations (Home Services Membership Platform) Job Category Web Development → Full-Stack Development Project Description We’re building Pactly, a SaaS platform that helps home service companies (HVAC, pest control, lawn care, and similar trades) manage recurring membership and service-agreement programs. A working front-end prototype already exists (React), demonstrating the core product: member management, plan management, a renewals/dunning queue, and a campaign builder. We need an experienced full-stack developer to build the real backend and integrations underneath it — turning the prototype into a production, multi-tenant SaaS product. This is not a beginner project. It involves real payment processing, OAuth integrations with third-party business software, and multi-tenant data security. We’re looking for someone who has done this kind of work before, not someone learning it on our project. Scope of Work We have a detailed written specification ready to share upon connecting. In summary, the build includes: 1. Backend & database — Node.js or Python API, PostgreSQL, multi-tenant schema (organizations, users, members, plans, activity logs) 2. Authentication — managed auth provider (e.g., Clerk/Auth0/Supabase Auth) with organization-based roles 3. Jobber, Service Fusion and HouseCall Pro integration — OAuth 2.0 connection, initial data sync, webhook-driven updates, and write-back (creating jobs in Jobber from our app) 4. Stripe integration — Stripe Connect for membership billing, webhook handling for payment success/failure, dunning logic 5. Twilio integration — SMS reminders and campaign sends, inbound reply handling, opt-out (STOP) compliance 6. Background job system — scheduled sync, renewal detection, dunning retry checks, queued bulk messaging 7. Security & compliance basics — encrypted credential storage, tenant data isolation, PCI-minimal-scope billing flow, TCPA-compliant messaging We’re open to phasing this as multiple smaller engagements (starting with backend/auth foundation) rather than one large contract. Must-Have Skills & Experience • 4+ years of professional full-stack development experience • Proven Stripe integration experience — please point to specific past projects (Stripe Connect experience strongly preferred) • Proven OAuth 2.0 integration experience with any third-party API (token refresh, webhook signature verification, handling revoked/expired access) • Experience building multi-tenant SaaS applications with proper data isolation between customers • Comfortable working from a written technical spec and asking good clarifying questions, not just executing literally • Strong communication — this is a remote, async-friendly engagement, but we need clear written updates Nice-to-Have • Experience with Twilio or another SMS/messaging API • Experience integrating with field service management (FSM) or trade-industry software (Jobber, Housecall Pro, ServiceFusion, or similar) • Experience with background job/queue systems (BullMQ, Celery, or similar) • Familiarity with TCPA or PCI compliance basics How We’d Like to Work Together To start, we’re proposing a smaller fixed-price first milestone (backend schema, auth, and wiring the existing frontend prototype to a real API — no external integrations yet) so we can evaluate fit before committing to the larger integration work. If that goes well, we’d move to a second, larger engagement covering the Jobber, HouseCall Pro, Service Fusion, Stripe, and Twilio integrations. What to Include in Your Proposal 1. A specific example of a Stripe integration you’ve built (link or description) 2. A specific example of an OAuth-based third-party integration you’ve built 3. Your experience (if any) with multi-tenant SaaS architecture 4. Your availability and estimated timeline for the first milestone 5. Any clarifying questions the spec raises for you — we’d rather see good questions than a proposal that assumes everything Additional Notes We have a complete written engineering specification (data model, API surface, integration details, and milestone breakdown) ready to share with serious applicants.