There is as validation process that runs on demand and while testing that validates contents, schema, etc... in each collection. We should add persisted samples validation to your workstream, something similar to how we validate timeseries buckets.

Readme: https://github.com/10gen/mongo/blob/fd376da77021ba8a16a668ab26a8f41fe0f65bb5/src/mongo/db/validate/README.md 

Eg: https://github.com/10gen/mongo/blob/fd376da77021ba8a16a668ab26a8f41fe0f65bb5/src/mongo/db/validate/validate_adaptor.cpp#L1156-L1167