Backend Engineer, AI Infra & Large-Scale Systems

Dex; Greater London; On-site; GBP 90,000 - 130,000; Full time

Job summary

Dex is building an AI operating system for enterprise IT, partnering with teams to place engineers in impactful roles and provide context about the opportunity.

This backend role focuses on owning core platform components, including large-scale batch processing, the LLM gateway, and enterprise-grade auth/observability. The position requires in-person collaboration with the London team, five days a week.

Qualifications

• 3+ years of backend engineering experience with ownership over platform components.
• Experience designing distributed systems with queueing and batch processing.
• Familiarity with LLM infrastructure at scale, including token routing and failover.
• Proven track record building internal tooling or APIs to improve velocity.
• Ability to work in person with the team in London five days a week.

Responsibilities

• Design and build core backend platform components to enable rapid shipping.
• Develop and scale batch job infrastructure handling large data volumes.
• Engineer the LLM gateway with token throughput management and provider failover.
• Establish robust auth and observability defaults for enterprise reliability.
• Build internal tooling and APIs to accelerate product development and team efficiency.

Skills

Backend engineering

Distributed systems

LLM infra

Internal tooling

On-site London

Job description

Dex is building an AI operating system for enterprise IT, partnering with teams to place engineers in impactful roles and provide context about the opportunity.

This backend role focuses on owning core platform components, including large-scale batch processing, the LLM gateway, and enterprise-grade auth/observability. The position requires in-person collaboration with the London team, five days a week.