.NET MAUI Community Standup: CoreCLR & Profiling your MAUI app

TL;DR

• 1

  CoreCLR becomes the default in .NET 11: Shimon explained that MAUI is moving from Mono to CoreCLR on mobile, with Android and iOS previews already using it by default and an eventual removal of the Mono escape hatch.

• 2

  Startup gains can be real, but app size is the trade-off: In one internal Microsoft MAUI app on a low-end Samsung phone, default CoreCLR was roughly equal to Mono, while full ReadyToRun improved startup by about 30% but increased app size by nearly 70%.

• 3

  Custom startup profiling is now possible with MAUI Labs CLI: A new MIBc profiling flow lets developers record their app's hot path, bundle the generated profile, and AOT only the code that matters most for startup instead of inflating the whole app.

• 4

  AI is changing how the MAUI team ships code: Gerald and David said Copilot-authored and Copilot-reviewed PRs have dramatically increased throughput since late February, especially for repetitive work like Apple API bindings, backlog fixes, and tests.

• 5

  Release quality has held up despite much more code landing: David said the repo saw more regressions with the increased pace, but they were not highly impactful, were fixed quickly, and did not meaningfully worsen quality relative to the volume of shipped work.

• 6

  Upgrading to .NET 10 is not optional anymore: .NET MAUI 9 went out of support on May 12, and the team shared reports from developers seeing major crash reductions after upgrading, including one app that saw about 75% of Android crashes disappear.