Platform Site Reliability Engineer

📋 Job Overview

The last era of AI scaled on a single bet: bigger models, more identical chips, more data. As problems grow more complex and the requirements of intelligence more diverse, that bet is breaking down. Real-world problems are heterogeneous: no single model or chip can solve them alone. The next era of AI requires heterogeneity at the infrastructure level - diverse models on diverse chips, each with distinct strengths, co-evolving into systems of capability that move the Pareto frontier of what is possible. That's what we are building.

🏢 About Callosum

Callosum is the Intelligent Systems Company. We started from questioning what actually creates intelligence. We believe there is no single answer, but rather a system-level solution. We co-evolve models, workflows, and silicon together to show that intelligence does not come from a single component, but it emerges from the diversity of co-optimised mechanisms working together and aware of each other. Heterogeneity will define the next era of compute, and is a principle that holds in biological, neuronal, and economic systems alike.

🎯 The Role

Our platform is the production system our customers route real traffic through. When it degrades, their product degrades. You will own its operational health end-to-end: SLOs, observability, incident response, deployment discipline, and capacity planning across heterogeneous compute backends. As the platform scales to millions of concurrent requests across heterogeneous compute, the work shifts from building the operational foundation to defending it under conditions most teams never encounter.

✅ Key Responsibilities

• Service-level objectives, monitoring, alerting, and observability
• On-call and incident response: runbooks, escalation, blameless postmortems, and follow-through
• Capacity planning and the operational side of running across heterogeneous compute backends

📌 Required Qualifications

• Strong SRE or production-engineering background running customer-facing systems at scale
• Fluency with modern operational tooling: observability stacks, container orchestration, infrastructure-as-code, CI/CD
• Experience owning incident response and driving reliability improvements.
• Compliance execution experience

⭐ Desirable Experience

• Open-source contributions to relevant infrastructure, or production systems whose scale and complexity you can speak to in detail
• Early-stage and AI-native company experience

🎁 Benefits

• Competitive Salary, determined by skills and experience
• Equity & Ownership
• Private healthcare
• Visa sponsorship and relocation benefits
• Tools, space, and setup for best work
• Inclusive workplace with equal opportunities

🛂 Visa & Eligibility

We offer Visa sponsorship and relocation benefits to hire the best in the world.