What's the fastest c++ build pipeline you've achieved ?

Trying to get a realistic picture of what's actually achievable on a large c++ codename before we commit to anything. We're at 450k LOC, full clean builds sitting around at 55 minites on a 16-core machine. Incremental builds are manageable but a full rebuild after a branch switch or a CI run is painful. We've moved to Ninja, cache is in place, worst of the header bloat is cleaned up. At this point it feels like We're pushing against a hardware ceiling rather than a tooling one. Distributed compilation seems like the logical next move , but I'm also wondering if there's something between local optimizations and a full distrubuted setup that actually moves the needle. Anyone hit similar numbers at this scale and seen meaningful improvements?

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