Senior Full Stack Engineer Contractor- Contract until 31st August
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Senior Full Stack Engineer Contractor- Contract until 31st August
450–600 / Month
Location
United Kingdom
Experience
Senior
Posted
Jul 7, 2026
Apply by
August 6, 2026
Applicants
0
Early applicantEasy applyContractWork from Home
Job Description
**Who are OnCommerce?**
OnCommerce is a global selling platform that powers a growing network of retail channels, including:
- **OnBuy** - The only marketplace in the world to give customers instant Cashback on everything
- **easyShop** - An all-new marketplace created in collaboration with the easy® family of brands
- **Comet** - The iconic UK tech brand making its return later this year
OnCommerce is growing fast, launching new brands and scaling to power the future of ecommerce.
**Be Part of the Story**
OnCommerce is constantly evolving. Everyone here plays a hands-on role in shaping what comes next, building brands that make an impact across global markets. There’s no red tape or rigid corporate structure; just smart people taking ownership and figuring things out as we build something big together. The pace is fast, priorities shift, things aren’t always perfectly set up, and you’ll often need to get stuck in and solve problems. But if you thrive in that kind of environment, you’ll have real influence, real ownership, and the chance to grow with a rapidly scaling business.
**The Role**
**End-to-End Engineering Ownership**
- 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
**Front-End Excellence**
- 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
**Back-End & Platform Engineering**
- 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
**Quality & Engineering Standards**
- Own quality to production — testing is embedded, not a phase
- Write and maintain automated tests (unit, integration, end-to-end)
- Participate in and lead code reviews to ensure high engineering standards
- Debug, troubleshoot, and resolve issues across the stack
**Performance & Scalability**
- Optimise systems for performance, reliability, and scale
- Work with large-scale data systems (MySQL, NoSQL, search platforms)
- Identify bottlenecks and proactively improve system efficiency
**Collaboration & Leadership**
- Work in cross-functional teams with Product, Design, QA, and other Engineers
- Mentor and support less experienced engineers
- Communicate technical concepts clearly to non-technical stakeholders
**Essential**
- 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
**Desirable**
- Experience in eCommerce or marketplace platforms
- Cloud experience (GCP)
- Experience with NoSQL (e.g. Couchbase) and Search platforms (e.g. Constructor & Solr)
- Experience working in microservices architecture
**This role is UK remote role you must be based in the UK and have full right to work in the UK.**
**The day rate is £450- £600 per day. DOE Please confirm your outside IR35 day rate upon application. This a contract until the end of August 2026**
**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.
Key Responsibilities
- Design, build, and maintain full-stack solutions across UI, APIs, and backend systems
- Translate product requirements into scalable, production-ready systems
- Build responsive, high-performance user interfaces using modern JavaScript frameworks
- Design and develop scalable services and APIs
- Maintain and evolve legacy systems while building modern architecture
- Write and maintain automated tests including unit, integration, and end-to-end tests
- Lead code reviews to ensure high engineering standards
- Optimize systems for performance, reliability, and scale
- Work with large-scale data systems and identify bottlenecks
- Collaborate with cross-functional teams including Product, Design, and QA
- Mentor and support less experienced engineers
Skills Required
PHPLaravelJavaScriptES6+ReactVueAngularRESTful APIsMySQLNoSQLCouchbaseMongoDBMicroservicesRabbitMQPub/SubGCPDockerCI/CDCommunicationLeadershipMentoringProblem solvingOwnershipeCommerce platformsMarketplace platformsConstructorSolr
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