Four years, no frozen release

Twenty years of acquisitions left Subversion in the powertrain division, Mercurial in an acquired telematics team and Git everywhere newer. Three servers, three permission models, three audit trails for one regulator.

A big-bang migration had already been attempted and abandoned: sixty build agents were pinned to fixed SVN URLs inside a certified build environment that could not be revalidated on the project timeline.

All three systems moved behind one RhodeCode instance with a single permission model, without converting a single repository. The legacy toolchain kept building against the same URLs.

Teams then converted when their own release calendar allowed it — nine hundred repositories over four years, never more than a handful in flight at once.

The migration stopped being a programme with a deadline and became routine maintenance.

Calibration data in multi-gigabyte binaries needed largefile handling configured per repository before conversion, and two teams discovered undocumented hook scripts only when their builds broke.

Every repository is now governed by one permission model with one audit trail, and the remaining Subversion repositories are a choice rather than a liability.