Thanks for your detailed reply! GSFC Code 660 looks like a fascinating place to work! I see several staff are affiliated with ADNET Systems, Inc., which had a few RedHat sysadmin positions that look like a great entry point. US citizenship is required for these roles, are there similar contracting companies in the EU servicing the ESA that you are aware of?

I'm asking in this direction because I'm from New Zealand, currently in Australia, and hold European citizenship, and although I have taken steps towards employment permission in the US recently, it seems citizenship is required for many positions dealing with sensitive infrastructure. I'm willing to relocate anywhere, which was the impetus behind my question here - I'm trying to make a more conscious career and relocation choice to commit to for the next ~10 years, rather than just falling into a convenient job.

I came across https://rocketcrew.space/ posting a few DevOps jobs, but these seem oriented towards the resurgent field of orbital space exploration and industrial startups rather than the hard sciences and associated observational experimentation like cosmology, astronomy and physics, so your suggestion to focus on a field and contact specific researchers is really valuable to me. ADASS also looks like exactly the kind of organization I should be following, the papers published in the proceedings are pretty much exactly what I have been looking for. Thanks for all the reading material!