I didn't write the job listing, but I understand it as being interested in OSS contributions, maybe already being a contributor to some projects.
> hiring someone to contribute to open source, makes that person likely represent interest of the corporation
That's true, and this is why my team is active within the project by having a member on the Technical Oversight Committee and several others in SIGs. The point is not to push our own agenda, we have made a lot of changes that are mainly relevant to our use cases and that don't necessarily make sense to upstream. Whenever we work on features that we know others would benefit from, we engage with the project's relevant committees and make the changes requested in pull request reviews.
To be clear, I don't speak for my employer and this is only my own experience. Not all teams are like this.
> I think much better idea to "contribute back" is to actually pay the existing contributors rather than having own pet one.
Contributing features and supporting existing contributors in other ways are not incompatible. We have a whole team working on this code base full time, and so do other companies. Of course all of these people collaborate. This project is not really run by volunteers but mostly receives contributions from a number of companies (originally created at Netflix, large parts came from Google, etc).
edit: See TOS members here for a list of the companies involved: https://cd.foundation/blog/2022/11/01/new-spinnaker-technica...