You package an app, push it through Intune, and the portal says installed. Then you log on to the machine and it is not there. Or it fails with a code like 0x87D30068 and no clue why. Win32 app deployment is where most Intune packaging time disappears. Almost every failure comes down to a few things, and once you know them the hit rate goes right up.
The detection rule is the number one cause
Intune does not really know if your app installed. It runs a detection rule and believes the answer. Get the rule wrong and the portal lies to you in both directions, says installed when it is not, or keeps reinstalling something that is already there. Point detection at something that genuinely exists after a good install, the actual exe with a version check, or a registry key the installer writes, not a guess. A wrong detection rule is behind most "it says installed but it is not" reports.
Install context and the commands
Decide system or user context and mean it. Most apps want system so they install for the machine regardless of who logs on. An app that writes to a user profile needs user context, and getting this backwards gives you silent no ops. Get the install and uninstall command lines right, with the silent switches, and test them by hand on a clean machine before you ever wrap them. If it does not install silently from a command prompt, it will not install through Intune.
Requirements and dependencies
A requirement rule that is too tight quietly holds the app back and it never even tries. Check the OS, architecture and disk rules are not excluding the very machines you are targeting. If the app needs something else first, a runtime or a framework, set it as a dependency so Intune installs them in order rather than failing halfway.
Read the log instead of guessing
When something fails, the answer is almost always in the IntuneManagementExtension log on the device. It shows the detection result, the exit code, and what the installer actually did. An error code on its own means little, the log around it tells you whether it was detection, a bad switch, a requirement block, or the installer itself. Learn to read that one file and most Win32 mysteries solve themselves.