Reduce build time for Android App in Release

[FlavioGoncalves-Cayas]

Hi everyone,
for one of our customers I am developing an app that will be whitelabeled into many visually different apps with slightly different configuration with the same codebase during build-time.
Each app has it's own Pipeline in Azure DevOps for iOS and Android, where the build app step alone for Android takes about 10-15 minutes. I assume most of the time is spent during conversion from .dll to .so files. Now take that times >20 (apps) this means the build process for all apps takes several hours.

Is there any way to reduce that time since the codebase itself is mostly the same - only some configuration files, .csproj properties, resources etc. are switched out before building?

Would it be beneficial to put most of the shared code in it's own NuGet Package/DLL?
Or is there some way to build .so files in advance in a seperate pipeline and feed into the build for the multiple apps?

Any ideas?

Tagging @jonathanpeppers @jpobst for visibility.

[jonathanpeppers]

@FlavioGoncalves-Cayas can you "diff" the two apps? Something like:

• Unzip two .apk files to two folders
• Compare the two folders in your favorite diff tool, like WinMerge
• What is different?

I imagine what you are describing is possible but would require lots of MSBuild knowledge to make it work. Depending on what the diff is; I'm not sure I would recommend it.

Would you be better off fanning out your build into multiple lanes in parallel? Azure DevOps can do this pretty easily, for example ours looks like this:

[FlavioGoncalves-Cayas]

I just took a look with FileMerge on MacOS. There are diffs in

• all .dex files
• all .so files
• assemblies/assemblies.blob
• some resources, even some which seem to be android system related, like drawable/$avd_hide_password__0.xml (maybe because of different colors in colors.xml?)

I guess it's not as easy as one might imagine.

Would you be better off fanning out your build into multiple lanes in parallel? Azure DevOps can do this pretty easily, for example ours looks like this:

I wasn't necessarily looking to make it faster, but save costs and resources by removing redundant steps in the build.

[jonathanpeppers]

So many files are different, I'm not sure I would attempt it. The time you would spend to get it to work (in your salary, for example), seems like it would cost more than the saved CI $$ dollars.

You might consider just running the pipeline ~daily? Or on-demand? Easy way to save?