DevOps Engineer (Senior) - Bazel Monorepo

Fractile; Bristol (VA); Hybrid; USD 120,000 - 160,000; Full time

Job summary

Fractile is seeking an experienced engineer for a hybrid role based in Bristol or London. The chosen candidate will control the Bazel ecosystem, focusing on its implementation from scratch in a dynamic deep-tech environment.

They will undertake responsibilities including designing Bazel rules and optimising CI pipelines, enabling breakthroughs in ML hardware and software development. The position promises significant impact, collaboration across teams, and ownership of software build processes.

Qualifications

• Candidate should have 5+ years in software or infrastructure engineering.
• 3+ years of experience with build systems required.
• Strong knowledge of Bazel is essential.

Responsibilities

• Design and own Bazel rules and extensions.
• Scale the monorepo across various languages.
• Create reproducible, multi-language build pipelines.
• Optimise CI performance across large compute clusters.
• Define the developer experience for all engineers.

Skills

Strong experience with Bazel

Python scripting and automation

5+ years in software or infrastructure engineering

3+ years with build systems

Experience with CI/CD for large-scale products

Tools

GitHub Actions

Containers

Job description

Bristol or London

Hybrid: Three days on-site

We’re looking for an engineer who wants to own Bazel at scale and build the tooling that powers every part of Fractile, from ML models to kernel drivers to hardware simulation. This is a greenfield Bazel role in a fast-growing deep-tech company building a new class of ML hardware and software from first principles.

What you’ll work on

• Designing and owning Bazel rules and extensions
• Scaling our monorepo as we grow across Python, C++, Rust, SystemVerilog and ML workloads
• Creating reproducible, multi-language build pipelines
• Optimising CI performance across large compute clusters
• Defining the developer experience for every engineer at Fractile
• Contributing upstream to Bazel rules we depend on

Why this role is unique?

• No legacy — you’re building the Bazel ecosystem from scratch
• Extreme variety — ML, compilers, kernel drivers, simulators, hardware verification
• High impact — your work becomes the backbone of the entire engineering organisation
• Deep collaboration with Simulation, Runtime, and Hardware teams
• Real ownership — you shape how Fractile builds software

What we’re looking for

• 5+ years in software or infrastructure engineering
• 3+ years with build systems
• Strong experience with Bazel
• Python scripting and automation
• Experience with CI/CD for large-scale products

Bonus

• ML pipelines
• GitHub Actions
• Multi-language build systems
• Containers