This is only pragmatic if you accept the first order assumption that they must use GCP. Which, maybe it's the case for a dev at Discord, but it's a somewhat idiosyncratic choice to call pragmatic. Seems like a lot of developer time and GCP charges to overcome limitations of GCP and wind up with something that's far more brittle than just running your databases on real hardware.
They already run on gcp and presumably have a negotiated agreement on pricing. Their core competencies don’t include managing hardware. Migration off is deliberately expensive and hard. Own hardware still needs a story for backup and restore in lieu of attached volume snapshots, or they’d have to figure out if their database can do something for them there. Any of the above are good reasons to not migrate willy nilly, in fact the only reason to migrate is that either you can’t do what you need to in the cloud or the margins can’t support it.
