Platform & DevOps·Pipelines, promotion and GitOps
it worked in staging and broke in production, because staging had one replica, no mesh and a different database size.
Environment parity
Also calleddev/prod parity, staging fidelity
How closely lower environments resemble production in configuration, topology, data shape and scale. Perfect parity is unaffordable, so the useful discipline is knowing exactly where the differences are and which classes of bug those differences will therefore let through. Undocumented divergence is what turns a green staging run into false confidence.