A seed-stage, physician-founded startup had a mature clinical rules engine that nothing enforced, and a thin proof of concept with no nursing workspace. There was no CI gate that could block a merge, an escalation cascade that had never actually fired, a single contractor as a continuity risk, and no path to a HIPAA-grade production environment ahead of a first pilot with a senior-care operator.
I joined in July 2026 as founding engineer for the nursing side and took over all engineering in August. I built the RN Command Board (patient status, event lifecycle, handoffs, messaging, shift notes) and the Provider Command Board (accept, assign, structured instructions with per-instruction acknowledgement), and hardened the escalation cascade so a Red alert can never stop unowned. Paging goes out by SMS, web push and native push with PHI-free payloads.
The clinical rules are deliberately deterministic, with no LLM in the loop. The clinician's simulator is extracted as the oracle, I port its logic into typed modules, and a generated conformance harness (now around 17,000 cases) grades the engine against it. A single disagreement fails CI.
I also built the Expo mobile app for shared nursing-station phones (lock-on-leave, screenshot blocking, Red alerts that break through Do Not Disturb), a fair-scheduling proof of concept, the AWS CDK infrastructure with an isolated Multi-AZ production tier, and the compliance paper trail: SOC 2 scope, security review, incident response and DR procedures, and the production-readiness checklist that gates real PHI.
TypeScript, Turborepo, NestJS, Drizzle, PostgreSQL (RDS), Temporal, Zod, React 19, Vite, TanStack Router, Expo / React Native, WorkOS, Twilio, AWS CDK, ECS Fargate, CloudFront, CodePipeline, Infisical, Playwright, Vitest, Claude Code
Dev environment live since July 31, 2026. Staging and an isolated production tier were deployed and verified on October 22, 2026, with real PHI gated on the readiness checklist. The first pilot customer (four care homes) is provisioned in staging. The engine passes all 16,966 conformance cases at its current pin. About 680 commits and 410 PRs in four months.