Security Lead - Member of Technical Staff
Possible
Sponsorship likelihood
This employer issued few or no visas recently
Not disclosed
Salary
Not disclosed by employer
£48,500
Going rate
Skilled Worker going rate
This role likely qualifies for a Skilled Worker visa
SOC 2135 (88% match) is an eligible occupation, with a going rate of £48,500, 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.
Worth checking: this could also be SOC 1259 (Managers and proprietors in other services not elsewhere classified, If managing security team/budget is the main duty), which is not on the eligible-occupation list. Ask CALLOSUM LTD what the duties actually are.
New graduate or PhD holder? Pick one of the lower rates.
What each route needs for this job
| 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 |
|---|---|---|---|---|
2135 Cyber security professionals Most likely code | £34,000 | £38,800 | £43,700 | £48,500 |
2133 IT business analysts, architects and systems designers Also possible | £38,400 | £43,900 | £49,400 | £54,900 |
1259 Managers and proprietors in other services not elsewhere classified Also possible | £33,400 | £41,700 | £41,700 | £41,700 |
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. How the Home Office picks the code
About the role
About Us
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.
About the Role
Callosum operates across a broad technical surface: APIs used by customers directly, orchestration software deployed across heterogeneous clusters, agentic systems with access to tools and data, and physical compute infrastructure that we operate ourselves. These products run in very different environments and for customers with very different security requirements, from shared cloud infrastructure through to sovereign, on-premise, and isolated deployments.
This role owns how security is designed and assured across that landscape. You will set the security architecture, translate customer and deployment requirements into concrete technical expectations for engineering teams, and ensure that the guarantees we make can be demonstrated in practice. You will lead security engagements across customers, infrastructure partners, and external technical reviewers, while building and managing the team responsible for security across Callosum.
What You'll Do
Define security architecture and requirements across our API, orchestration stack, agentic systems, and physical infrastructure
Translate complex security requirements into specific engineering work, measurable guarantees, and verifiable evidence
Lead security assurance for sensitive deployments from initial requirements through technical review and approval
Build and lead the security team across architecture, threat modelling, adversarial evaluation, incident response, and operations
What Sets You Apart
Experience personally owning a demanding security assurance or sensitive deployment process end-to-end
Strong technical foundations in infrastructure or security engineering, with the depth to challenge architectural decisions
Experience securing sovereign, on-premise, air-gapped, multi-tenant, or other high-assurance environments
Experience building and leading security teams, with strong judgement around risk, prioritisation, and engineering trade-offs
What We Offer
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.
Where this offer sits in the market
Cyber security professionals (SOC 2135) · UK · ONS ASHE 2025 · basic pay · ~30k in sample- Middle half £43,680–69,316
- Median £51,376
- Going rate £48,500
- Threshold £41,700
- New entrant £34,000–43,700
Similar sponsored roles
See all UK visa jobsNo close matches live right now.
Browse more sponsored jobs at CALLOSUM LTDAbout sponsorship for this role
Does this job guarantee visa sponsorship?
Not 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.
What salary is needed for this role to be eligible?
The offer must clear both the general threshold and the SOC 2135 going rate of £48,500. New-entrant and shortage discounts can lower it.