We deploy distributed, multi-language, centrally Lisp/SBCL servers as well. A few specifics that I'd point out:<p>Many of SBCL's optimizations are fine grained selectable, using internal SB-* declarations. I know I was at least able to turn off all optimizations for debug/disasm clarity, while specifically enabling tail recursion so that our main loop wouldn't blow up the stack in that build configuration. These aren't in the main documentation; I asked in the #sbcl IRC channel on FreeNode.<p>You can directly set the size of the nursery with sb-ext:bytes-consed-between-gcs, as opposed to overprovisioning the heap to influence the nursery size. While we've run in the 8-24GB heap ranges depending on deployment, a minimum nursery size of 1GB seems to give us the best performance as well. We're looking at much larger heap sizes now, so who knows what will work best.<p>While we haven't hit heap exhaustion conditions during compilation, we did hit multi-minute compilation lags for large macros (18,000 LoC from a first-level expansion). That was a reported performance bug in SBCL and has been fixed a while back. Since the Debian upstream for SBCL lags the official releases quite a bit, it's always a manual job to fetch the latest versions, but quite worth it.<p>Great read, and really familiar. :-)