03 / About

A frontend dev,
measuring his work.

Mainul Islam, photographed in 2026.Mainul Islam, 2026
CurrentlyOpen to
roles & projects
FocusA/B Testing
& Frontend

I'm a frontend developer working remotely since 2019.

My focus is frontend you can measure: building reliable A/B tests and conversion experiments for real businesses. I started in freelance frontend work and moved steadily toward experimentation, the part of the job where you can prove whether a change actually worked. Over the last few years, that adds up to 500+ A/B tests shipped across ecommerce and SaaS — alongside frontend builds for startups and individuals across the UK, India, Slovakia, Austria, Australia, and Canada.

I've been a frontend A/B testing developer with Conversion.com for 4+ years, building production tests on enterprise platforms. Now actively open to new opportunities, full-time remote or contract.

On how I work: everyone uses AI now, the skill is using it well enough to actually finish what you start. I treat Claude Code like a junior engineer who needs a clear spec, the right context, a tight scope, and an honest review pass. That workflow is what made a solo, full-stack experimentation platform finishable in 1.5 years, including 2 earlier versions I scrapped, and a year+ of planning and architecture, banked on what those false starts taught me.

— Stack & Skills

What I build with.

Core

JavaScript (ES6+)TypeScriptReactNext.jsHTMLCSS

AI as co-engineer

Claude CodeSpec-driven promptingContext managementAgentic workflowsMulti-file refactorsAI code review

Styling

SCSSTailwind CSSBootstrapModern CSS

Experimentation

OptimizelyAB TastyKameleoonVWOAdobe TargetQubit

Backend, data & CMS

Node.jsExpress.jsGraphQLPostgreSQLDrizzle ORMMongoDBFirebaseClickHouseCloudflare WorkersWordPressHeadless CMS

Tooling & PM

GitVitestPlaywrightTurborepoVS CodeTampermonkeySlackJIRAAsana

Outside of code.

Outside of work I run a YouTube channel for quiet travel videos. I'm drawn to mountains and the sea — anywhere a little further from the screen.

Want the
long version?

Every role, the stack, and a few projects worth a closer look. Read online, save as a PDF, or just share the link.