Systems Engineer: AI Security & Low-Latency Infra

Refractal Ltd; Greater London; Hybrid; GBP 90,000 - 120,000; Full time

Benefits offered by this job

Competitive salary

Equity

Performance bonus

Product influence

Leadership path

Visa sponsorship

Job summary

Refractal Ltd is hiring a systems engineer to own the services and infrastructure that keep the production environment secure and reliable. You will work across enforcement runtime, data integrity, tenant isolation, and cloud infrastructure, delivering low-latency, tamper-evident systems with strong observability.

You will build and operate a high-performance enforcement pipeline, manage events and streaming services, and implement multi-tenant controls while maintaining tight production

Qualifications

• Strong backend or infrastructure experience across distributed systems.
• Proficient in Python and scripting for automation.
• Hands-on observability and distributed tracing, OpenTelemetry preferred.
• Experience building services that perform under load with proper timeout/retry/backpressure.
• Expertise with Postgres, Row-Level Security, migrations and multi-tenant controls.
• Hands-on with containers, cloud infra, CI/CD and production security.

Responsibilities

• Build and operate a low-latency runtime enforcement pipeline with predictable failure behaviour.
• Own observability and tracing across agent actions, tool calls, model calls, and enforcement decisions.
• Build tamper-evident evidence storage and enforce multi-tenant isolation across data paths.
• Create reliable event and streaming services with safe handling for load, retries, backpressure and disconnections.
• Build infrastructure for red-team tasks, evaluation workloads, and model-serving services.
• Own cloud infrastructure, continuous delivery, secrets, artefact verification, and production trust boundaries.

Skills

Backend systems

Python

Observability

Load handling

Postgres & RLS

Containers & CD

Job description

Refractal Ltd is hiring a systems engineer to own the services and infrastructure that keep the production environment secure and reliable. You will work across enforcement runtime, data integrity, tenant isolation, and cloud infrastructure, delivering low-latency, tamper-evident systems with strong observability.

You will build and operate a high-performance enforcement pipeline, manage events and streaming services, and implement multi-tenant controls while maintaining tight production