You might be interested working for European company SYSGO with offices in Germany, France and Czech Republic. We are developing real-time OS named PikeOS targeted for safety & security industry.
It's SMP microkernel OS running on architectures with MMU support. Main feature is virtualization/separation of application into time/resource partitions; e.g. multiple critical tasks are running together with unsafe tasks (Linux) on single CPU.
After recent acquisition by Thales we are expecting much more work in following years, so new workforce is wanted here.
https://www.sysgo.com/company/job-offers/