Hi, I'm interested in this compile-time issue because I'm facing the same kind of issue in some of my own projects. I'm extensively using Boost so I don't really know if it comes from it or if it comes from my code (which similarly uses a lot of templates). Anyway, could you share a little bit over how you can find out what are the compile-time hitters? I've got some sources taking like 40s to build with gcc and it's getting really annoying. Are they some best practices when using template meta-programming? Some tricks to know about what pattern is slow and what's quicker for the compiler? For example -- as this is a phoenix thread -- could you share some examples of what took time in phoenix and how you fixed it? I've tried Steven Watanabe template profiler but got a lot of trouble with the STL complaining about its code being modified (which is true as the template profiler adds some code to it). Best regards, -- Beren Minor