I'm Henry Coles, one of Scotland's two Java Champions, with extensive experience designing, developing and testing software systems, and mentoring and training development teams. I'm the creator of pitest, the world's leading mutation testing system for the JVM used everywhere from banks through to the control systems for the Large Hadron Collider at CERN. My book, Java for Small Teams, has been adopted as a reference on Java style by organisations including UK Government Digital Services. I specialise in software quality and have helped numerous organisations modernise their codebases and tackle technical debt. Recently I’ve been assisting AI startups creating RAG chains on the JVM.

Henry Coles

I'm Henry Coles, one of Scotland's two Java Champions, with extensive experience designing, developing and testing software systems, and mentoring and training development teams. I'm the creator of pitest, the world's leading mutation testing system for the JVM used everywhere from banks through to the control systems for the Large Hadron Collider at CERN. My book, Java for Small Teams, has been adopted as a reference on Java style by organisations including UK Government Digital Services. I specialise in software quality and have helped numerous organisations modernise their codebases and tackle technical debt. Recently I’ve been assisting AI startups creating RAG chains on the JVM.

Available to hire

I’m Henry Coles, one of Scotland’s two Java Champions, with extensive experience designing, developing and testing software systems, and mentoring and training development teams.

I’m the creator of pitest, the world’s leading mutation testing system for the JVM used everywhere from banks through to the control systems for the Large Hadron Collider at CERN.

My book, Java for Small Teams, has been adopted as a reference on Java style by organisations including UK Government Digital Services.

I specialise in software quality and have helped numerous organisations modernise their codebases and tackle technical debt.

Recently I’ve been assisting AI startups creating RAG chains on the JVM.

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Experience Level

Expert
Expert
Expert
Intermediate
Intermediate
Intermediate

Language

English
Fluent

Work Experience

Principal Engineer at Arcmutate (CDG)
January 1, 2020 - Present
Provide commercial extensions to the Pitest mutation testing tool, integrating with Git and pull request workflows, and improving support for frameworks such as Spring. Also provide consultancy for AI startups generating RAG chains that run on the JVM.
Director at Pitest Consulting Ltd
January 1, 2019 - January 1, 2020
Provided consultancy, coaching and training to development teams.
Principal Developer at SolarWinds
January 1, 2019 - January 1, 2019
Provided support and guidance to development teams working on SolarWinds’ core remote management product.
Head Of Development Practice at NCR
January 1, 2013 - January 1, 2019
Improved how software was developed within the Edinburgh office by creating a role that provided mentoring, training and consultancy to multiple teams. This was a hands-on position, including pairing, development and design.
Technical Designer at Bright Grey
January 1, 2007 - January 1, 2013
Joined the development team as a senior developer before promotion into the technical designer role.
Senior Developer / Technical Team Leader at LogicaCMG
January 1, 2000 - January 1, 2007
Worked within the Energy and Utilities division on many green field projects, including as technical lead of the flagship “Instant Energy” smart metering system. I led development from initial R&D work through to delivery of a system serving multiple clients around the world.

Education

Postgraduate Research at University of Nottingham
January 1, 1999 - January 1, 2000
BSc Biomaterials (2.1) at University of Nottingham
January 1, 1996 - January 1, 1999
BSc Chemistry at University of Nottingham
January 1, 1995 - January 1, 1996
A Levels at Ermysted’s Grammar School
January 1, 1989 - January 1, 1994

Qualifications

Java Champion
April 16, 2026 - April 16, 2026

Industry Experience

Software & Internet, Energy & Utilities, Financial Services, Professional Services

Experience Level

Expert
Expert
Expert
Intermediate
Intermediate
Intermediate