Hi Georges, There have been quite some improvements those last weeks on the performance of loading classes and methods. But we are still waiting for the https://github.com/pharo-project/pharo/pull/5292 to be integrated. And you have to encapsulate the loading code into: SourceFiles deferFlushDuring: [...] and use the latest pharo 8.0 image. You can give a try with this and tell us how it goes! Cheers, Vincent -----Original Message----- From: Pharo-dev On Behalf Of George Ganea Sent: Friday, 6 December 2019 17:08 To: pharo-dev at lists.pharo.org Cc: Chis Vasile Andrei <dedal18 at yahoo.com> Subject: [Pharo-dev] code loading performance Hi all, Currently loading GToolkit takes quite some time (arount 18 minutes at the best of times) we were wondering if there���s been any attempts at improving code loading times in Metacello/Monticello. Or mabye there are some ideas on how one might start doing something like this? Cheers, George