Hi, I'm James Calmus, a frontend engineering leader based in London with over a decade of experience building and scaling web platforms across insurance, healthcare, and digital products. I specialise in React, Next.js, and Angular, with a focus on performance, architecture, and developer experience. I enjoy leading teams, delivering high-impact projects, and improving technical systems and collaboration across disciplines.

James Calmus

Hi, I'm James Calmus, a frontend engineering leader based in London with over a decade of experience building and scaling web platforms across insurance, healthcare, and digital products. I specialise in React, Next.js, and Angular, with a focus on performance, architecture, and developer experience. I enjoy leading teams, delivering high-impact projects, and improving technical systems and collaboration across disciplines.

Available to hire

Hi, I’m James Calmus, a frontend engineering leader based in London with over a decade of experience building and scaling web platforms across insurance, healthcare, and digital products.

I specialise in React, Next.js, and Angular, with a focus on performance, architecture, and developer experience. I enjoy leading teams, delivering high-impact projects, and improving technical systems and collaboration across disciplines.

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Experience Level

Expert
Expert
Expert
Expert
Expert

Language

English
Fluent

Work Experience

Head of Frontend Engineering at Policy Expert
May 1, 2025 - Present
Lead frontend strategy and a team of 12 engineers, defining standards across architecture, testing, and delivery. Provided hands-on support across complex projects and performance improvements.
Tech Principal / Tech Lead / Senior Engineer at Policy Expert
January 1, 2021 - January 1, 2025
Delivered £5m+ revenue impact via redesigned quote journey; built GraphQL platform serving 1.5m users; improved core site performance by 96%; led teams and mentored engineers.
JavaScript Developer at Digital Theatre
January 1, 2020 - January 1, 2021
Built streaming platform using Next.js, Node.js, AWS.
Software Architect at Orvista Health
January 1, 2018 - January 1, 2020
Built NHS platform with Angular 8 admin system and role-based access; designed full-stack architecture.
Full Stack Developer at Wilder Digital
January 1, 2019 - January 1, 2020
Built Angular-based social and campaign platforms.
Freelance Developer at Independent / Freelance
January 1, 2026 - Present
Delivered high-performance sites and a custom CMS for clients including CleanUpGambling.com (Next.js) and Gamban4Greyhounds.com (React).
Frontend Developer at CleanUpGambling.com
January 1, 2026 - Present
Custom CMS and high-performance site built with Next.js.
Frontend Developer at Gamban4Greyhounds.com
January 1, 2026 - Present
Campaign platform built with modern React stack.

Education

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Qualifications

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Industry Experience

Software & Internet, Healthcare, Professional Services, Media & Entertainment, Financial Services