
Possible
Sponsorship likelihood
This employer issued few or no visas recently
£101,000 – £192,000 / year
Salary
Above P75 for SOC 2134
£54,700
Going rate
Offer clears by 1.8×
This role likely qualifies for a Skilled Worker visa
SOC 2134 (68% match) is an eligible occupation, with a going rate of £54,700, and CALLOSUM LTD is a licensed sponsor. That is our reading of the rules. Whether they issue a Certificate of Sponsorship is still their call.
This could also be SOC 2133 (IT business analysts, architects and systems designers). We read the code off the advert, so it is our best guess, not the employer's.
New graduate or PhD holder? Pick one of the lower rates.
| Occupation code | New entrant 70% of going rate | STEM PhD 80% of going rate | Relevant PhD 90% of going rate | Standard rate 100% of going rate |
|---|---|---|---|---|
2134 Programmers and software development professionals Most likely code | £38,300 Clears | £43,700 Clears | £49,200 Clears | £54,700 Clears |
2133 IT business analysts, architects and systems designers Also possible | £38,400 Clears | £43,900 Clears | £49,400 Clears | £54,900 Clears |
We use the lowest threshold across the plausible codes. Likelihood is Possible at most when the pay clears only a lower rate, or only under a less likely code. A mark is for the top of the advertised pay. How the Home Office picks the code
We’re living through a Cambrian explosion of intelligence: new models and new chips, each specialised for different tasks, are arriving all at once. The result is a new era for AI, one of radical heterogeneity.
Callosum is the Intelligent Systems Company. We believe the next generation of AI won't be defined by any single model or chip, but by intelligent systems in which hardware and intelligence co-evolve. We are building the infrastructure that unifies heterogeneous compute across the full stack. This opens a new axis of scaling intelligence: a dynamic system that tailors itself to what each workload actually needs, whether that's speed, cost, precision, or whatever unit comes next.
The last era scaled on a different bet: one bigger model, more of the same chip, more data. That bet is running into structural limits. Frontier models offer extraordinary capability at unsustainable cost, one that today's monolithic infrastructure was never designed to serve.
Our founding principle is that intelligence comes from many specialised systems working together, not from any single component. We build the software orchestration layer that co-evolves models, workflows and silicon into one system, delivering inference tailored to every workload, and demonstrating orders-of-magnitude leaps in capability and cost.
Because our software spans the full stack, our engineering team works directly with heterogeneous accelerators and frontier silicon, including Cerebras, d-Matrix, Intel, NVIDIA, AMD, Normal Computing, Tenstorrent, GreatSky, and Mixx. We are not stopping at today's chips: each new generation of silicon unlocks algorithms that couldn't run before, and we intend to be first to them, every time. If we get it right, it will belong to everyone building on it - not to any single vendor.
In our latest funding round, we raised $100M, led by Atomico with participation from Plural, DCVC and the UK Sovereign AI Fund’s first investment. With this, we are building the infrastructure for the next era of intelligence.
We are engineers and scientists based in London, working across the full depth of the stack. We are curious, intellectually honest, and building what doesn't exist yet. If you thrive on uncharted territory and are energised by the scale of the challenge, we'd love to hear from you.
The Applied AI team own Callosum's customer engagements end to end. You will work directly with customer engineering teams to understand their AI workloads, design and run rigorous evaluations against their production pipelines, integrate optimised workflows into their systems, and make sure the results hold in production.
At Callosum, Applied AI Engineers are the technical bridge between what customers run and what we build. What you learn shapes the research and platform roadmap. The evaluations you run are how we prove the technology in production. As an early member of the team, you will help build the methodology, tooling, and engagement practices the function runs on. The role is engineering-led: you will employ technical judgment to recognise what kind of system a problem needs and prototype it.
You will work closely with the engineers designing new intelligent systems, with the platform team that serves them, and directly with senior technical stakeholders on the customer side. We run a flat Member of Technical Staff structure. Responsibility and scope grow with what you demonstrate, including leadership of the Applied AI function as the team scales.
Customer engagement from first workload scoping through evaluation, integration, and production deployment
Design and run rigorous evaluations on customers' production workloads: set success criteria, instrument the comparison, present results to their engineering teams
Develop deep technical understanding of customer systems (retrieval pipelines, agentic workflows, code intelligence stacks) and design optimised Callosum workflows
Integrate Callosum workflows into customer environments and support them through to stable production
Work with our research and platform teams to turn what you learn into general product capability
Build the team's shared methodology: evaluation harnesses, integration runbooks, and engagement standards
Exceptional technical depth, demonstrated through any of: production systems at scale, research that shipped, or an early/founding role where you owned the system end to end
Experience with LLM serving infrastructure, agent orchestration, or retrieval systems
Rigour in evaluation or benchmarking work
A bias for action, comfort with ambiguity and a strong sense of ownership
Experience working directly with external engineering teams, whether as a forward deployed engineer, solutions architect, technical consultant, or comparable customer-facing role
Familiarity with novel accelerator platforms
Experience at an early-stage company or in a founding-engineer role
Competitive Salary, determined by skills and experience
Equity & Ownership
Private healthcare
We offer Visa sponsorship and relocation benefits to hire the best in the world
We work in person at our London office. You'll have the tools, space and setup to do your best work, and if you have specific needs, just tell us
We're committed to building an inclusive workplace where everyone feels welcome, and believe in equal opportunities for all.
This description is the source posting as it read when we added it. We are not affiliated with CALLOSUM LTD, so check their own site for the current details.
Even the bottom of this range, £101,000, beats the market's 75th percentile. CALLOSUM LTD pays in the top quarter for this occupation.
No close matches live right now.
Browse more sponsored jobs at CALLOSUM LTDNot necessarily. CALLOSUM LTD holds a sponsor licence, but sponsorship for a specific hire is always the employer's decision. Be upfront in your application that you'll require it.
The offer must clear both the general threshold and the SOC 2134 going rate of £54,700. New-entrant and shortage discounts can lower it.