JOBS · CALLOSUM CAREERS (ASHBY)
London, in person, salary based on skills. Callosum states it offers visa sponsorship, but wants substantial hands-on LLM systems experience and production engineering.
The role sits on the software side of systems co-design and builds systems that are served at scale. The company says the team works in person at its London office and explicitly offers visa sponsorship and relocation support.
Salary is described as competitive and determined by skills and experience. No closing date is published; applications appear open on the Ashby page.
The advert asks for substantial hands-on experience with modern LLMs, production engineering, empirical benchmarking and independent work. Strong signals include LLM inference and serving, fine-tuning, reinforcement learning, distillation, constrained generation, research or meaningful-scale deployments.
This is not an entry-level AI training role. Unless your portfolio demonstrates real deployed systems or research, the probability of progressing is low. Still, the sponsorship wording is unusually clear and a tailored application could test the market.