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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.…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

Web Developer, Front-End Developer, Full Stack Developer

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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.…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.

Skills

Experience Level

Expert

Expert

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).