Senior Full Stack Engineer – Contractor

OnBuy

Senior Full Stack Engineer developing and maintaining OnBuy’s core commerce platform across front-end and back-end systems. Delivering scalable solutions that impact GMV and customer experience.

Posted 6/18/2026contractRemote • 🇬🇧 United KingdomSenior💰 £400 - £650 per dayWebsite

Tech Stack

Tools & technologies

AngularCloudDockerGoogle Cloud PlatformJavaScriptLaravelMicroservicesMongoDBMySQLNoSQLPHPRabbitMQReactVue.js

About the role

Key responsibilities & impact

This is a critical role responsible for building, scaling, and evolving OnBuy’s core commerce platform across both front-end and back-end systems.
As a Senior Full Stack Engineer, you will own engineering delivery end-to-end; from customer-facing experiences to underlying services and data systems.
You will operate within a cross-functional team and be accountable for shipping high-quality, scalable solutions that directly impact GMV, seller performance, and customer experience.
Design, build, and maintain full-stack solutions across UI, APIs, and backend systems.
Translate product requirements, designs, and wireframes into scalable, production-ready systems.
Own features from concept → development → testing → release → monitoring.
Build responsive, high-performance user interfaces using modern JavaScript frameworks.
Translate UI/UX designs into clean, maintainable code.
Optimise applications for speed, scalability, and usability.
Design and develop scalable services and APIs.
Work across monolith and microservices architecture (Laravel / PHP services).
Maintain and evolve legacy systems while building modern, scalable architecture.

Requirements

What you’ll need

Strong full stack engineering experience, owning end-to-end delivery
Proven backend expertise in PHP (Laravel)
Strong JavaScript (ES6+) skills with modern frameworks (React/Vue/Angular)
Experience designing and building RESTful APIs and scalable systems
Experience with MySQL and NoSQL databases (e.g. Couchbase, MongoDB)
Strong understanding of system architecture and microservices
Experience with event-driven systems (e.g. RabbitMQ, Pub/Sub) and cloud environments (GCP)
Familiarity with Docker and CI/CD pipelines
Strong engineering practices: testing, code quality, and production ownership
Experience in eCommerce or marketplace platforms (Desirable)
Cloud experience (GCP) (Desirable)
Experience with NoSQL (e.g. Couchbase) and Search platforms (e.g. Constructor & Solr) (Desirable)
Experience working in microservices architecture (Desirable)

Benefits

Comp & perks

This role is UK remote role you must be based in the UK and have full right to work in the UK.
Our Commitment
OnBuy is an equal opportunities employer. We are dedicated to creating a fair and transparent workforce, starting with a recruitment process that does not discriminate on the basis of gender, sexual orientation, marital or civil partnership status, pregnancy or maternity, gender reassignment, race, colour, nationality, ethnic or national origin, religion or belief, disability, or age.
Just a heads up — we never use WhatsApp or any messaging apps to contact candidates. If someone reaches out this way, it isn’t us and let the recruitment team know.

ATS Keywords

✓ Tailor your resume

Applicant Tracking System Keywords

Tip: use these terms in your resume and cover letter to boost ATS matches.

Hard Skills & Tools

full stack engineeringPHPLaravelJavaScriptES6+ReactVueAngularRESTful APIsMySQL

Soft Skills

end-to-end deliverycross-functional teamworkaccountabilityproblem-solvingcommunicationadaptabilityattention to detailtime managementcollaborationownership