Senior Engineers – Multi-Tenancy, Workflow Engine, Document Automation (Greenfield, AI-Native Build)

We're building a greenfield, multi-tenant platform for internal enterprise use. Design work is done and a functional prototype exists — we're assembling a small team of engineers to take it to a production MVP. This is not a staff-augmentation posting. We're looking for people who have built this kind of system before and can reason about the architecture, not just implement tickets. The problem space: The platform is configurable and API-first: workflows, individual steps, forms and other capabilities can be configured and triggered independently within a tenant context. Concretely, that means: Multi-tenancy — tenant isolation, per-tenant configuration and branding, role-based access, automated tenant provisioning Workflow engine — ordered, branching, rules-driven sequences that route tasks across multiple parties with SLA tracking Document generation & form building — upload a PDF, place fields on it, map each field to a data model, generate filled documents at runtime Digital signatures — multi-party, order-enforced signing with cryptographic integrity (hashing, PAdES sealing, trusted timestamping, keys in a hardware-backed store) and a tamper-evident audit trail Immutable document storage — WORM retention, long-term archival, verifiable on retrieval Integrations — REST/webhooks into existing enterprise systems and external verification services, built to survive outages Micro-frontends and a mobile-first user experience We're looking for depth in one or more of Multi-tenant SaaS architecture — you've made the isolation call (pooled vs. siloed) and lived with it Document engineering — PDF manipulation, field mapping at scale, digital signatures, PKI, compliant archival Workflow/rules engines — configurable, versioned, data-driven rather than hard-coded Systems integration — SSO/OIDC, queuing, retries, idempotency AWS + infrastructure-as-code, CI/CD, observability React/TypeScript + Node.js at senior level How we work We're building AI-native from day one — AI used heavily across architecture, development, testing and delivery to keep the team small and move fast. You should be genuinely fluent working this way, and comfortable owning the output regardless of how it was produced. Engagement ~3–5 months, full-time. Several hours of daily overlap with US Pacific required, working alongside our architect, product owner and engineering leads. A confidentiality agreement is required before project details are shared. In your proposal, please tell us: A system you've built involving multi-tenancy, document generation, or e-signature — what the architecture was and what you'd do differently now How you'd approach mapping arbitrary uploaded PDFs to a structured data model so non-technical admins can maintain them How you use AI in your day-to-day engineering work Your availability and rate