Jan 2024 – Present
Senior Software Engineer Cachix
In charge of product and infrastructure for Devenv and Cachix, including developer tooling, production infrastructure, deployments, and CI.
- Developed the modern Rust build of Devenv, focusing on performance, maintainability, and cross-platform support.
- Maintain and develop plug-and-play modules for Devenv covering 50+ language modules, 43 services, and 17 integrations.
- Designed Cachix’s release pipeline: declarative infrastructure, release-fenced migrations, rolling auto-scaling deployments, and customer AMIs.
- Taught a hands-on Devenv workshop at NixCon 2024 in Berlin.
- Discovered a memory-corruption vulnerability in Nix’s archive parser with potential root code execution GHSA-vh5x-56v6-4368.
Sep 2022 – Dec 2023
Software Engineer Cachix
Worked on Cachix’s binary-cache service in Haskell, optimizing storage, uploads, and observability.
- Cut cloud spending by 75%: migrated binary cache storage from S3 to Cloudflare R2 with zero downtime through dual reads, background migration, and upload cutover.
- Rebuilt the upload pipeline to optimize scaling costs.
- Released Cachix Deploy: a scalable service for pull-based deployments of Nix machines, with automatic rollbacks and observability.
- Built the Cachix Daemon: a tool to stream and cache Nix builds concurrently.
- Co-built Flakestry: a public open-source Nix flake registry.
- Upstreamed Rosetta support for NixOS on Apple Silicon.
Jan 2019 – Aug 2022
Independent Software Engineer
Transitioned to functional programming and declarative infrastructure, focusing on Haskell, Nix, and Elm. Worked on open-source projects.Sep 2016 – May 2018
Lead Software Engineer Campusboard
Led the company’s pivot from a university marketplace to a UK student-accommodation reseller. Ruby on Rails, Ember.js, PostgreSQL, Redis, Elasticsearch, AWS, and Heroku.