Senior Full Stack Developer/Engineer

Senior Full Stack Engineer for a pre-launch B2B SaaS product with real-world complexity: distributed background processing, third-party API integration, and a dense desktop-first UI. Join as the first dedicated engineer and help shape the architecture before launch.

We are a small, self-funded software company building a new B2B SaaS product. The product is pre-launch and intentionally quiet for now; shortlisted candidates will receive the full product description and architecture document under NDA before any commitment beyond an initial conversation. This is the first dedicated engineering hire on the product. The core infrastructure and architecture baseline already exist, including environment strategy, scaling triggers, integration constraints, and the decisions that would be expensive to reverse. We want someone who can evaluate that plan critically, improve it, and help turn it into a durable production system. The technical challenge is not raw user traffic. It is background sync driven by connected third-party accounts, ongoing worker throughput, and correctness in the face of multiple external APIs that fail in different ways. Rate limits, per-tenant quotas, distributed locking, backoff, and graceful degradation are day-one concerns. On the front end, you will build a dense, responsive browser-based interface with a custom hand-written SVG visualization that is central to the product experience. The MVP is desktop-first and fully web-based, with tablet and mobile support in browser; native mobile apps are later-stage work. We are looking for a senior engineer who has operated production systems that integrate with multiple external services on a schedule, can reason about tradeoffs across frontend and backend, and is comfortable owning ambiguity in a small team.

- 6+ years of professional software engineering experience, with significant full-stack ownership - Strong experience building and maintaining production web applications end to end - Demonstrated experience integrating with multiple third-party APIs or external platforms - Hands-on experience with background jobs, queues, schedulers, or worker systems - Familiarity with distributed locking, idempotency, retries, backoff, and failure recovery - Comfort working with rate limits, quotas, expirations, polling, and event-driven sync patterns - Ability to design and ship responsive browser interfaces for complex, information-dense workflows - Experience building custom data visualizations or working directly with SVG/canvas rendering is a plus - Strong debugging, architecture review, and production incident troubleshooting skills - Able to work remotely across Americas time zones and communicate clearly in a small team - Comfortable with a contract-to-hire arrangement and an NDA-protected pre-launch environment TypeScript end to end. Node.js 22 with NestJS or Fastify on the back end, React 18 with Tailwind CSS on the front, PostgreSQL 16 behind PgBouncer, Valkey for cache and queue, and BullMQ for background jobs — all running on DigitalOcean App Platform, Azure, or AWS as separate API, worker and cron components, deployed from a versioned app spec through GitHub Actions. Prisma or Drizzle for data access, Zod for validation, TanStack Query for server state, shadcn/ui on Radix for components, Vite for builds, Pino for structured logging, Vitest for tests Mobile, after MVP. Swift/SwiftUI for iOS and Kotlin/Jetpack Compose for Android — fully native, two codebases, both consuming the same public API as the web client. Not a screening requirement for this role.