We hire freelancers who are experts in particular projects to fix bugs, add features we need, etc. Some of those are on a "retainer" basis (eg. $8000 for 80 hou

We hire freelancers who are experts in particular projects to fix bugs, add features we need, etc. Some of those are on a "retainer" basis (eg. $8000 for 80 hours work on an OSS project for us during a year where we can "consume" that time on bugs/features we need), others are on a fixed-price per-project basis, others are hourly. Generally in these cases the freelancer will be a core contributor to the OSS project in question, and come through our contacts in the project community. Posting to the -dev mailing list as either a client needing something done or a freelancer available for work is probably a good way to start. In some cases these freelancers have shopped-around work to previous clients like us -- eg. "if I can get $X from you and $Y & $Z from these other clients, I can work to make this large/necessary change to the project happen" -- which maybe we don't need enough to pay for ourselves but we'd like to see. Otherwise we expect team members or contractors working on projects involving OSS to contribute any fixes & improvements upstream where practical, and we book this into project timelines & budgets.