Harry Grumbar

About Me

I'm a full-stack developer based in London. I have strengths in front-end development using popular libraries and over 7 years' experience building and delivering software.

Having worked in highly FP-oriented teams I am a strong proponent of functional programming in modern scalable applications. A focus on testable and predictable code is core to my programming principles.

When building for the front-end I enjoy using React with which I work with almost exclusively in TypeScript. I am a strong believer that a modern type system and compiler brings many benefits to the reliability of one's code and helps and greatly reduces the number of errors.

When I'm not building React apps I also enjoy tinkering with server applications in Node and Elixir as well as working on open-source projects.



Software Engineer / May 2018 - Present

Bulb is a renewable energy provider that heavily relies on its technology to differentiate itself from the competition. Among the first full-time engineers to be hired I've worked across a number of areas of the business delivering software and working cross-functionally to help shape and develop new products.

We make extensive use of data to drive the way we design features. New features are often rolled out as experiments using toggles while we measure their performance.

A few of the projects and responsibilities I've been involved with:

  • Designed and built a new business-critical payment system (Bulb Pay) on urgent timelines.
  • Re-architected and designed new authentication infrastructure to allow members to access their Bulb accounts more easily and securely.
  • Built complex back-end tasks to detect and manage revenue-related issues. These jobs involved processing large volumes of data efficiently and reconciling state changes between runs.
  • Been extensively involved in techical hiring and interviewing, and mentoring junior developers.


Software Engineer / May 2016 - May 2018

Working in a diverse team using multiple languages and tools I was mainly responsible for building web user interfaces for the principle products, "Pro" and "Direct", that serve the users of Goodlord, a platform for streamlining the process of letting a property. We worked in small squads following agile principles delivering iterative work as well as infrastructure and dev-ops improvements.

  • Built and maintained the core business logic and UI component library for both platforms in React/TypeScript and accompanying living style guide.
  • Made key architecture and library decisions to ensure that developer happiness was kept high and the codebase remains testable and maintainable.
  • Championed the usage of atomic and functional styles to help control the CSS footprint of our applications. We also experimented with css-in-js approaches to further improve code reusability and componentisation.
  • Participated in team "guilds" (Functional Programming, Front-End Dev, Testing, Dev-ops) that allowed us to learn alongside our colleagues and further our knowledge in the respective areas.


CFA Society UK

Investment Management Certificate / 2011

University of Bristol

Master of Engineering, Civil Engineering / October 2006 - June 2010

Skills and Interests

I enjoy spending my time keeping up to speed with the latest developments in tech and the software startup world as well as trying to further my programming abilities such as delving into category theory and FP principles.

I am also a keen sportsman and particularly enjoy cycling, tennis, skiing, and football as well as being an avid traveller.