This sounds like an organisational issue, not a technical, and I predict that this simply won't scale organisational-wise. It sounds like they have given no thought about their platform architecture, deploy pipelines, testing strategies, ... It's probably not yet causing issues because they're working in a small team, but rectifying this later will be an absolute pita.
That said, at scale, having a big staging/test/... can be impossible, but then things are split up organisationally, each team managing/service group/... managing their own environments, being responsible for the reliability/stability and availability towards other teams.
Also, with service meshes it has become feasible to actually test in production so you can let select users end up on specific (test) versions of a certain backend service.
That said, at scale, having a big staging/test/... can be impossible, but then things are split up organisationally, each team managing/service group/... managing their own environments, being responsible for the reliability/stability and availability towards other teams.
Also, with service meshes it has become feasible to actually test in production so you can let select users end up on specific (test) versions of a certain backend service.