We helped a handful of teams migrate from Ingress to Gateway API in 2023
and 2024. Most of them are still on it. A few rolled back. The lesson is
less about the API and more about how the migration interacts with the rest
of the platform.
What stuck
The split between GatewayClass, Gateway, and *Route. Once teams
internalized the boundary between "who owns the listener" and "who owns the
route," conversations got shorter.
What broke
Status. The conformance test suite is good; what it doesn't cover is the shape of status reporting under contention. We saw three different implementations report "Ready" for incompatible reasons.
What we'd warn you about
Don't migrate the production envoy and the platform abstraction at the same time. Pick one. The temptation to do both is real and it has cost more than one team a weekend.