Cooperative customizations
When you've done all you can to make CiviCRM fit your specialized needs through configuration,
and to modify your workflows to fit the software,
and you still need to close that gap a little further ...
Then you might have a business case for creating a custom extension.
Of course, that falls under customization: Creating or modifying computer code (usually PHP and JavaScript files) to add or alter functionality.
And you already know that if you do that, you could be taking on the burden of long-term bug-fix support for your customizations.
But there's a way you can minimize that support burden:
Design your extension so that it could be useful to others.
Then share that extension with the CiviCRM community, by publishing it in the CiviCRM extensions directory.
How does this reduce the burden of maintaining your customization?
There's no guarantee, but if you play it smart, you probably find that:
People you don't know will install and use your extension.
Software developers you don't know will spot, and even contribute fixes for, bugs in your extension — before you even find them yourself.
That's the beauty of open-source software, and of the CiviCRM community in particular: you help others by offering your customization, and they help both themselves and you by helping to improve and maintain it.
It happens literally every day.
So:
If you've decided that you need to create a custom extension, there's very little downside to availing yourself of the cooperative nature of the open-source community. It’s the classic “win-win” situation.
All the best,
A.