Arsenale is closing the sovereign AI stack — application layer, model weights, eventually the silicon underneath. The work is engineering-led, ambitious in scope, and resident in the UK. If that sounds like the next thing you want to spend a few years on, we want to hear from you.
We are not currently running a structured hiring round, but we do keep a register of strong engineers and operators we want to talk to when capacity opens. The areas below are where we expect the first additions.
Low-level Linux, kernel-adjacent work on unified-memory inference, scheduling, and the runtime layer beneath the model. Comfortable across C, Rust, and the parts of the operating system most application engineers stay away from.
Python, FastAPI, frontend, the agent runtime, the customer dashboard, the update channel. The work touches the parts customers actually use; care for craft on those surfaces matters as much as throughput.
Model fine-tuning on the workloads our customers run, agent design, evaluation harnesses, post-training. Bias toward engineers who can ship something that survives contact with a real customer over researchers who can write a paper about why it might.
UK public-sector procurement experience, defence or central-government rolodex, comfort with G-Cloud / DOS / DASA / DSIT routes. The product is technically ready; getting it into the right buildings is the bottleneck.
These aren't slogans. They're the actual constraints under which the company operates and the kind of person who thrives here.
You will run things end-to-end. There is no committee to defer to and no hand-off layer to hide behind. The corresponding cost is that you cannot escape the consequences of your decisions.
We prefer the small thing that works to the large thing that almost works. Code that survives review is code someone else could maintain after you leave.
Our customers buy us because the alternative ships their data to someone else. Decisions that compromise that posture for engineering convenience are not on the table.
Disagreement is registered immediately, in the room, in writing. Politely. Once. Then the team aligns and moves.
UK-based. Hybrid by default — most of the team work from where they choose, with regular gathering in London. Defence-adjacent work may require physical presence and the appropriate clearances.
All full-time staff receive equity. We will be specific in writing about scheme, vesting, strike price, and dilution paths before any offer is signed.
We hire candidates with the existing right to work in the UK. We are not currently set up to sponsor visas; this may change as the company scales.
Send a CV, a few lines about what you want to work on at Arsenale, and links to anything you've built that you're proud of. We read every application and reply to the ones we want to talk to.
careers@arsenale.ai →