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@lists.pharo.org Cc: Chis Vasile Andrei <dedal18@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 thereâs 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