Conversion - Full-Stack Developer at This is Gain Ltd

Full-Stack Developer 

About the Role 

We’re looking for a talented and motivated Full-Stack Developer to join the Conversion I/O tech team. You’ll work alongside a close-knit group of engineers building the I/O platform — a proprietary experimentation operating system used by leading brands across EMEA and North America. 

You’ll contribute across the full stack, from backend APIs to modern frontend components, working on features that directly impact how we build and manage experimentation programs. 

Roles & Responsibilities 

Day-to-Day 

• Build and maintain features across the full stack using Laravel (PHP) on the backend and Vue.js 

• Write clean, well-structured code and participate actively in peer code reviews 

• Collaborate with the team via async channels (Microsoft Teams, Jira) and scheduled video calls across timezones 

• Debug and resolve issues across the full stack — from database queries to frontend rendering 

• Contribute to sprint planning, ticket estimation, and technical discussions on architecture and approach 

Longer-Term 

• Take increasing ownership of platform features and technical decisions as you build familiarity with the codebase 

• Help shape tooling improvements and contribute ideas for making the team’s development workflow more efficient 

• Support integrations with third-party platforms including A/B testing tools (Optimizely, VWO, Kameleoon) and analytics APIs 

Must-Have Skills 

These are the skills we’ll screen for in every candidate. You should be confident using these in production environments. 

Backend 

• PHP 8.1+ with Laravel — including Eloquent ORM, migrations, service providers, middleware, queue jobs, and Artisan commands 

• MySQL — query optimisation, indexing, and relational database design 

Frontend 

• JavaScript (ES6+) — solid core language understanding 

• Vue.js (v2+) including Vuex and Vue Router 

• SCSS/SASS and Bootstrap 5 

Tooling & Process 

• Git and GitHub — branching, pull requests, and GitHub Actions CI/CD 

• Docker — comfortable working in containerised local environments 

• Strong English communication skills — written and verbal, for async collaboration across timezones 

• Experience working with legacy code alongside modern patterns 

Good to Have 

These skills will make a candidate stand out, but we don’t expect all of them. Familiarity with even a few of these is a positive signal. 

Technologies 

Domain Knowledge 

React, Next.js, Redux 

Typescript 

RESTful API design 

Node.js 

GraphQL 

Redis, Pusher / Laravel Echo 

PHPUnit 

OAuth / JWT authentication 

AWS (S3, SES), Nginx 

DigitalOcean container registry 

Vite, Axios, Zod, ESLint 

Element UI / Ant Design Vue 

TipTap / ProseMirror, D3.js 

Understanding of A/B testing principles and experimentation methodology 

Familiarity with platforms such as Optimizely, VWO, or Kameleoon 

Google Analytics API integration 

Jira API