Nice write up. At Thread we did a similar thing. Admittedly our codebase is ~10% as big, but incrementally adding linters for incompatible code, and keeping th

Nice write up. At Thread we did a similar thing. Admittedly our codebase is ~10% as big, but incrementally adding linters for incompatible code, and keeping the CI green, helped loads. We only had about 2-3 days of engineering time to ship the final version, the rest was done in 10% time.