What leaving would take
Four scenarios, each with its risk level and timeline — turning a dead end into a decision you can weigh. Full transition is estimated at 8–14 months.
Vendor leaves, no handoff
CriticalCatastrophic: the backend can't be updated without the vantage/* packages and infrastructure knowledge is lost. Northwind would have to negotiate source access and repo transfer — or rebuild.
Vendor leaves, full source handoff
HighA 6–12 month learning curve: Northwind must set up private package hosting and recreate CI/CD, with no tests to validate changes along the way.
Add a second developer alongside the vendor
ModerateSteep onboarding (3–6 months to productive) — the CLAUDE.md docs target AI, not humans, and infrastructure is undocumented. Builds resilience while the system runs.
Vendor continues, add oversight (recommended)
LowLowest risk first step: don't replace the vendor — verify Northwind can. Embed a QA engineer and the build checklist answers, within 30 days, whether Northwind could operate independently.