Full-Time

Cloud Systems & Resource Orchestration

Member of Technical Staff

Callosum

Callosum

11-50 employees

Orchestrates AI workloads across heterogeneous hardware

Compensation Overview

£101k - £192k/yr

+ Equity + Visa sponsorship + Relocation benefits

London, UK

In Person

Category
Software Engineering (1)
Required Skills
Graphics Processing Unit (GPU)
Kubernetes
Computer Networking
Infrastructure as Code (IaC)

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Requirements
  • Strong experience with Kubernetes internals, including custom controllers, schedulers, device plugins, custom resource definitions, and the Dynamic Resource Allocation framework.
  • Experience building or operating multi-cloud infrastructure, with detailed knowledge of networking, storage, and compute differences between major cloud providers.
  • Familiarity with GPU and accelerator resource management in cluster environments, including MIG, time-slicing, device plugins, and topology-aware scheduling.
  • Experience with infrastructure as code, fleet management, and reliability engineering for large-scale heterogeneous systems.
Responsibilities
  • Design and build multi-cloud orchestration systems that abstract provider-specific differences behind a unified deployment and scheduling layer.
  • Extend Kubernetes, particularly Dynamic Resource Allocation, to support heterogeneous accelerator topologies and capabilities and multi-agent artificial intelligence workflows.
  • Implement intelligent load balancing and placement strategies across cloud providers, regions, and hardware types.
  • Build control plane systems that efficiently allocate and manage heterogeneous accelerator capacity while preserving hardware-specific strengths.
  • Collaborate with an Accelerator Systems Software engineer to surface low-level scheduling primitives into the orchestration layer.

Callosum builds a software platform that manages and coordinates AI workloads across multiple, diverse hardware types. It orchestrates how different AI models run together on chip architectures from Nvidia, AMD, AWS, Cerebras, SambaNova, and more, treating the compute environment as an ecosystem and assigning tasks to the most suitable hardware to improve speed and accuracy while reducing cost. This makes it possible to avoid depending on a single hardware provider and to leverage the strengths of different accelerators in tandem. The platform integrates with major cloud providers (AWS, Google Cloud, Azure) and targets enterprises building complex, multi-agent AI systems as well as chip manufacturers validating new hardware. Callosum’s goal is to advance AI by enabling specialized, cooperative systems—similar to how the human brain works—rather than scaling a single model on one piece of hardware.

Company Size

11-50

Company Stage

Seed

Total Funding

$10.3M

Headquarters

London, United Kingdom

Founded

2025

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Simplify Jobs

Simplify's Take

What believers are saying

  • Plural led Callosum's $10.25 million round on February 26, 2026.
  • The UK's Sovereign AI Fund named Callosum its first investment on April 16, 2026.
  • Callosum says AWS co-engineering already supports multi-agent tool calling in production.

What critics are saying

  • Callosum still needs repeatable customer wins beyond launch-day demos and grant-backed pilots.
  • Cerebras, SambaNova, and hyperscalers can copy heterogeneous orchestration features inside eighteen months.
  • If Nvidia improves efficiency faster, Callosum's hardware-neutral pitch loses urgency and funding leverage.

What makes Callosum unique

  • Callosum orchestrates workloads across Nvidia, AMD, AWS, Cerebras, and SambaNova hardware.
  • ARIA's 2026 grant backs co-located heterogeneous clusters, validating the technical thesis.
  • The February 2026 launch positioned Callosum as cloud-agnostic, multi-model infrastructure for AI systems.

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Benefits

Health Insurance

Company Equity

Relocation Assistance

Growth & Insights and Company News

Headcount

6 month growth

-13%

1 year growth

-13%

2 year growth

-13%
The Executive Magazine
Apr 17th, 2026
Britain backs seven AI startups with $635M Sovereign AI Unit

Britain has launched the Sovereign AI Unit, a £500 million initiative to back homegrown AI companies through equity investment, supercomputing access and fast-track visas. Chaired by James Wise, the programme aims to ensure UK startups scale domestically rather than relocating abroad. Seven companies received initial backing. Callosum, founded by Cambridge PhD graduates, secured direct equity investment for its chip orchestration software. Six others — Prima Mente, Cosine, Cursive, Doubleword, Twig Bio and Odyssey — gained access to the AI Research Resource supercomputing network, each receiving up to one million GPU hours. Technology Secretary Liz Kendall said Britain must be "an AI maker rather than an AI taker". The unit operates with venture capital-style speed, offering compute power, visa support and government procurement access to prevent talent drain overseas.

Wired
Apr 16th, 2026
The UK Launches Its $675 Million Sovereign AI Fund

In a bid to minimize dependence on technology from other countries, the UK government is plowing resources into homegrown AI startups.

Plural
Feb 27th, 2026
Why we invested in Callosum | Plural

The infrastructure buildout behind frontier AI is one of the most impressive engineering feats in the modern era, with the amount of compute needed to train the most powerful models increasing over 1 billion times between 2010 and 2024.

Fortune
Feb 26th, 2026
Exclusive: Callosum, a startup looking to break Nvidia’s stranglehold on AI workloads, raises $10.25 million in new funding | Fortune

Founded by Cambridge neuroscientists and inspired by the brain, Callosum has developed a system for optimizing AI workloads across different chip types.

Callosum
Feb 26th, 2026
Introducing Callosum

Callosum - Co-evolving chips & intelligence