the frontier of LLM itself is now likely RL (a lot of vacancies revolve around it in placesbdoing LLM work ).
none of it matters if you find something to make that a lot of people love you for making it. that could be relatively simple optimizaitos in workflows etc.
not that making it will guarantee a job but it demonstrates recent and relevant skill in the area they work in.
for distributed systems my own mind goes to p2p dma, low level work to interconnect nics, gpus, nvme over fabric maybe, to build infra for AI systems. but on another planet (than mine) it can be agentic cloud stuff or agentic dev cloud platforms etc? (no clue there)