Backend engineering for US & EU SMBs
Hao Wu, founder · HexWell Systems LLC · Remote
Who I help
Small and mid-sized businesses that need reliable backend work—fully remote, on a B2B project basis (not open-ended staff augmentation).
What I do
- AI-built code, made maintainable — You moved fast with AI-assisted development; now the codebase is hard to change, test, or hand off. I stabilize architecture, tests, CI/CD, monitoring, and APIs so your team can own the system—not stay stuck on fragile prototype code.
- Custom internal tools — Replace spreadsheet-and-email workflows with something your team can run day to day.
- Integrations — Connect CRM, billing, ops, and internal systems via APIs.
Stack
Node.js, TypeScript, Python, Django, FastAPI, GraphQL, Postgres · AWS, Kubernetes, CI/CD
Selected work
- AWS SDK migration — US B2B marketplace. Zero-downtime v2→v3 across ~10 production codebases; shared rollout playbook.
- Platform consolidation — Remote-first US team (<5 engineers). Kubernetes, 30+ apps onto two instances; key backends re-platformed to Django with stable interfaces.
How I work
You work directly with me—not a bench or agency. Written specs and milestones; kickoff and major decisions on live calls. US Eastern and EU hours overlap; async between meetings.
Engagement
$100–$140/hr USD (B2B), with a cap on discovery · Pilots $8k–$15k for 1–2 weeks with clear deliverables—I confirm scope after a 15-minute fit call.
Contracts and invoices through HexWell Systems LLC (sole-member Oregon LLC). W-9 on request. ACH, wire, or Wise (USD).