Open Source Software Bounty Sites

I use a lot of open source tools in my day job that are currently unmaintained. We don’t have the bandwidth or support from management to pick them up and keep them running ourselves. Does anyone know of a marketplace that lets you put a bounty or pay a developer to maintain or add new features to an open source project. I did a few google searches and most of what I could find was strictly related to security or OSS software that was seeking maintainers.