Senior Full-Stack Engineer

ustwo is looking for an experienced Senior Full-stack Engineer to help us grow our digital product team. Specifically, we’re looking for someone who can work across the web stack, with experience in frontend web development as well as backend and infrastructure development.

As a developer you will work to solve difficult problems and build beautiful and intuitive products within a cross-functional team of technologists, designers, product owners and agile coaches.

How you’ll spend your time:

• You will design, develop, test, deploy, and improve digital products with a focus on full-stack development – from front-end, to backend, to infrastructure.
• You’ll work within a cross-discipline agile team (including product, design, test, and delivery) to refine work and collaborate on technical design and approach to build great products for our clients.
• You will be responsible for shaping the work you do, highlighting any areas of uncertainty, and ultimately delivering working software in a cross-functional team.
• You will be deep into code and be looked upon as an expert in your area of focus.
• You will be accountable for the delivery of complex tasks from end to end.
• You will work alongside our broader engineering team, who regularly share and learn from each other across projects.
• You will work closely with our clients – defining work, collaborating with their tech teams, and demoing your great work regularly.
• You’ll work closely with your colleagues in test/QA to ensure coverage of your work, contributing to automated test and build pipelines.
• You’ll contribute to your team by helping to shape ways of working, introducing new approaches, and horizon-scanning for new tools/technologies that could help us and our clients.

What we’re looking for:

• Excellent written and verbal communication skills.
• Experience building performant and usable web applications.
• Experience working within agile frameworks such as Scrum / Kanban, and most importantly, embodying the agile principles.
• Experience crafting high-quality user interfaces using HTML/CSS/JS.
• Experience with React, or another major web framework (e.g. Vue, Angular).
• Experience building and working with backend services (e.g. Node.js, serverless functions).
• Awareness of the most established front-end frameworks/libraries (React, Vue, Next, etc.), with experience in at least one.
• Experience working with databases, and working knowledge of different types of datastores and their characteristics (SQL / NoSQL / real-time, etc.).
• Knowledge of API design and experience with API integration / testing / design / implementation (e.g. GraphQL, REST, etc.).
• Experience with version control.
• Knowledge of CI/CD pipelines and typical integrations.
• Experience with unit testing (Mocha, Jest, Jasmine, etc.).
• Understand the importance of automated testing, and have experience implementing automated tests.
• Knowledge of the most common non-functional requirements (NFRs) including performance, reliability and availability, usability and accessibility, security, maintainability, scalability, observability, portability, and compliance (e.g. GDPR) and an understanding of how to build digital products that meet them.
• Experience with AI-assisted development: comfortable delivering quality code using CLI or editor-based LLM agents; using MCP servers; and maintaining up-to-date documentation.

Nice to have experience:

• Experience with deploying, hosting, securing, monitoring and scaling in the cloud (AWS, Azure or GCP).
• Experience with infrastructure as code (such as Terraform).
• Experience in building secure, reliable, performant, and usable web applications.
• Practical experience with TDD and / or BDD (using frameworks such as Mocha, Jest, Cucumber, Rspec, Capybara, Selenium, etc.).
• Experience with containerised services and orchestration (Docker, Kubernetes, Helm, etc.).
• Experience working with mobile development either in native and/or cross platform development (Swift, Java, Kotlin, React Native, Dart/Flutter).
• Experience delivering AI capabilities: context engineering, vector stores, RAG, on-device AI.

About You:

• Current in your practice. You have solid software development fundamentals and a working understanding of modern, best-practice software development practices and workflow.
• You keep up with the latest trends in technology.
• AI-native. You have embraced the AI productivity explosion and are highly-skilled in the delivery of production-grade code using LLM-enabled agentic AI.
• Highly collaborative. Able to work collaboratively in multidisciplinary teams of designers, developers and product managers using Agile and Lean principles.
• A clear communicator. You are capable of conveying ideas and breaking down concepts clearly to a diverse range of stakeholders (verbally and written).
• Open to sharing. Whether that be your thoughts, ideas and work in-progress.
• Desire to grow. You seek out opportunities to learn, promoting regular feedback with those who you work with.
• Resilient. You can handle pressure and work in a dynamic and fast-moving environment.
• Adaptable. You can handle ambiguity, are comfortable switching contexts and able to apply your practice across a range of industries, types of deliverables and goals.

Our full benefits package is available to all permanent and fixed term contract employment. We are committed to creating an inclusive environment for our colleagues, clients, community, and the users of our products. We don’t have all the answers but we’re on a journey, and we are learning together.