Senior Systems Integration Engineer — Architect & Build HHAeXchange (HHAX) EVV Integration

We're a HIPAA-compliant home care SaaS platform serving Minnesota 245D HCBS providers. We need a senior systems integration engineer to architect and build our HHAeXchange (HHAX) EVV integration end-to-end. We have a draft architecture and sandbox credentials in hand, but we want an experienced integrator to review it critically, identify weaknesses, and own the final design through to implementation. You should be someone who has designed and shipped complex third-party integrations before and can reason rigorously about failure modes — not just write code to a spec. The engagement starts with a paid architecture review: evaluate our current design, tell us what's sound and what isn't, and propose the approach you'd build — including your recommendation on tooling and patterns, with the reasoning behind it. From there we'll structure the build into milestones (visit submission + idempotency, reconciliation, cancellation handling, production cutover). Core stack: Go, PostgreSQL, AWS. We're open to your recommendations on supporting tools (job queue, reconciliation approach, etc.) — we want you to make the case for the right design, not just adopt ours. You'll be a fit if you have: - A track record architecting and building complex third-party / API integrations, ideally EVV aggregators (HHAeXchange, Sandata, Tellus) or healthcare / Medicaid systems - Deep Go and PostgreSQL expertise - Strong instincts for idempotency, reconciliation, state divergence, and failure handling The judgment to work within domain and regulatory constraints, not around them - US healthcare / HIPAA context (a strong plus)