Member of Technical Staff - Software Engineering (up to £220k)

Dex; Greater London; On-site; GBP 100,000 - 140,000; Full time

Job summary

Dex partners with a seed-stage AI lab in London/Paris to recruit a senior backend engineer. You will design and run the core backend platform that underpins interactive training environments, building APIs, runtimes, and data pipelines to support production-grade AI workloads.

The role is hands-on and senior, spanning architecture to implementation. You will own systems end-to-end, collaborate with researchers, and contribute to scalable, observable infrastructure on-site in London or Paris.

Qualifications

• Experience building distributed, data-intensive backends in production.
• Hands-on with cloud-native architectures and scalable systems.
• Proven ability to own complex subsystems from problem to production.
• Strong preference for on-site work in London or Paris.

Responsibilities

• Design and operate core backend services, APIs, and persistence layers for complex environments.
• Build distributed workflows and high-throughput pipelines for agent training data.
• Collaborate with AI researchers to translate experiments into scalable platform capabilities.
• Drive engineering rigor with testing, observability, IaC, and CD.

Skills

Distributed backend

Cloud platforms

TypeScript & Node.js

Go/Rust/Java/C++ familiarity

Ownership of complex systems

Tools

AWS

GCP

Job description

This role is with one of Dex's trusted partner companies. We work closely with their teams to truly understand their culture, goals, and what they're looking for, so we can match you with the right opportunity and give you context about the role before you commit to a process.

Dex is an AI recruiter agent that helps you run your job search. Tell Dex your stack, seniority, and what you want to build. We will manage your applications and surface other opportunities that are a fit.

The role

Frontier AI models are bottlenecked by data: the next generation of agents requires experiential training, learning through trial and error across real digital software. This seed-stage AI lab builds the interactive, resettable software environments that make this training possible, supplying critical training environments directly to multiple frontier labs. Founded by a repeat founder with a successful exit and backed by prominent tech angels and venture funds, they have grown to over 50 staff across London and Paris in roughly twelve months.

As a Member of Technical Staff, you will build the distributed platform underneath: the APIs, backend runtimes, persistence layers, and pipelines that generate, run, and scale dynamic environments.

This role is calibrated from Mid through Principal based purely on the technical scope and architectural ambiguity you can own, not your years of experience. This is not prompt engineering, wrapper building, or workflow orchestration; it is foundational backend systems engineering turning cutting‑edge agent training methods into reliable, production‑grade infrastructure.

The work

• Design and operate the core backend services, APIs, and persistence layers that instantiate, isolate, and reset complex software environments on demand.
• Build distributed workflows and high‑throughput pipelines to capture, process, and serve agent interaction traces directly into AI training loops.
• Partner closely with AI and curriculum researchers to translate raw experimental methods into hardened, scalable platform capabilities.
• Drive operational rigor across the engineering stack, setting standards for automated testing, observability, infrastructure as code, and continuous deployment.

What You Bring

• Demonstrated track record of building, debugging, and operating distributed, data‑intensive backend systems in production on AWS, GCP, or equivalent cloud platforms.
• Deep technical fluency in at least one typed language; their primary stack is TypeScript and Node.js, but background in Go, Rust, Java, C++, or similar is welcome.
• Proven history of independently owning ambiguous systems from raw problem statement to shipped production infrastructure, without needing detailed specifications.
• Committed to staying deeply hands‑on in architecture, implementation, and code; this seat is not for coordinators or pure managers.
• Able to work on‑site from their engineering hubs in London or Paris.