Senior Full-Stack Developer

We're on the hunt for.. As Senior Full-Stack Developer, who will play a key role in delivering end-to-end solutions across a range of projects. Building high quality user experiences while engineering the systems, APIs and integrations that make them robust, scalable and secure. You’ll work across both front-end and back-end systems, taking ownership of technical delivery from initial discovery through to deployment. You’ll collaborate closely with designers, project managers, and clients to translate requirements into scalable, maintainable, and well-structured technical solutions. You are confident working with modern development workflows and use AI tools as an accelerator to improve speed, exploration, and efficiency: while maintaining responsibility for code quality, correctness, and long-term maintainability. You pair this with strong full-stack fundamentals, clean coding practices, and a sharp eye for quality. This role requires clear communication and the ability to operate comfortably in ambiguous, fast-moving project environments. You will also act as a technical point of contact for clients, helping guide decisions and shape project direction. You have a methodical approach to problem solving and a genuine passion for technology and the evolving development landscape. Requirements What good looks like TECHNICAL PLANNING - Shape the technical approach and deliver solutions that support the client’s goals. - Liaise directly with clients and other stakeholders as the primary technical contact on a project, to understand their requirements - Conduct thoughtful research and creative problem solving of technical challenges - Lead architectural decisions and system design - Take ownership of projects from discovery through to delivery - Provide accurate technical estimates, working closely with project managers to develop a detailed delivery plan that accounts for technical dependencies and mitigates risk - Clear, confident and articulate presentation of appropriate solutions to clients, serving as their primary technical contact HANDS ON DEVELOPMENT (FULL-STACK) - Collaborate with designers and project managers to translate requirements into technical implementations. - Write clean, efficient, and maintainable code to create responsive and accessible user front-end interfaces. - Build and maintain scalable back-end solutions - Integrate with third-party services and APIs - Troubleshoot complex issues across the technical stack and propose practical, effective solutions - Deployment and Simple DevOps tasks as required AI ASSISTED & SPEC-DRIVEN DEVELOPMENT - Leverage AI tools and structured specs to accelerate delivery without sacrificing quality. - Apply spec-driven development practices - writing clear, structured specifications before and during implementation to keep AI-generated output accurate and aligned with intent.  - Use vibe coding techniques for rapid prototyping, exploring solutions and unblocking creative or technical decisions - this is an exploration and ideation practice, not a production delivery standard.  - Critically evaluate and review AI-generated code for correctness, security and maintainability before it reaches production.  - Stay current with the fast-moving AI tooling landscape and share tools and techniques that genuinely improve team output. TECHNICAL STANDARDS - Maintain high technical standards as the lead developer on your projects. - Clear, confident and articulate presentation of appropriate solutions to clients, serving as their primary technical contact - Collaborate with designers to ensure creative concepts are executed to spec. With a sharp eye for design fidelity, you care about maintaining visual consistency, polish and motion detail. - Ensure a high level of technical quality is maintained across projects from discovery to launch. - Follow best practices consistently across accessibility, security and performance. PASSION & CULTURE - Suggest ideas that improve our output, working methods and cultural activities. - Excited by and keen to learn about innovative technologies, such as AI  - Suggest ideas, tools and systems to maximise the effectiveness of our processes and work - Open to speaking at industry events on panels and raising the profile of Athlon in the public domain Five values that underpin everything we do Be Brave: Take chances, be ambitious. This is how you grow. Take risks, nothing can substitute experience. Take Ownership: Be a pro. Act like a champion. Own your domain. Not almost. All the way. Not most of the time. All of the time. Take ownership. Whatever it takes. Team First: Talent wins games, but teamwork wins championships. Respect the team. Treat others fairly. Build friendships. Disagree honestly. Share ideas candidly. We’re one team first. Craft Everything: Quality is never an accident; it’s always the result of intention, effort and skill. Craft everything. Passion Over Apathy: One person with passion is better than forty people merely interested. Use your passion as a catalyst to motivate and lead others. We expect you to be knowledgeable in: - Suggest ideas that improve our output, working methods and cultural activities. - Frontend languages (e.g. HTML, CSS/SCSS/Tailwind, JavaScript/TypeScript, frameworks like React and  Next)  - Experience with Backend languages ( Node.js or PHP). - Strong experience in one of WordPress (PHP) or modern JavaScript/Next.js headless CMS  ecosystems, with the ability and willingness to work across both. Exposure to both is highly desirable. - API Integration (REST , GraphQL) - GIT workflows, CI/CD automation - Cloud services (eg. AWS, GCP or Azure) - Solid understanding of software architecture and system design principles - AI coding tools — hands-on proficiency with tools such as Claude (claude.ai / Claude Code), Cursor, GitHub Copilot or similar LLM-assisted development environments - Spec-driven development — writing structured prompts, technical specs and implementation plans that guide AI-assisted workflows effectively - Vibe coding - comfortable using AI to rapidly prototype, iterate and explore solutions in fast-moving creative or technical contexts (prototyping and exploration; production code is always critically reviewed) Nice to have - Animation for web (eg. CSS animations, GSAP, Framer, Motion.js, Lottie etc) Your experience: - 6–8 years of full-stack development experience, with solid fundamentals across front end and back end - 2+ years actively using AI tools for code development — daily use of LLM-based coding tools in a professional or substantial personal project context (e.g. using Claude or Cursor as a core part of your workflow on a client project, not just occasional autocomplete) - Demonstrable experience applying spec-driven development and/or vibe coding methodologies - Experience working in an agency or client-facing environment preferred - Full-stack development skills, with a flexible tech-agnostic mindset How we work - This is a fully remote role - Your line manager is the Technical Lead - You will work in the Engineering Team Benefits - The chance to work on innovative, high profile projects that make an impact - A flexible work set-up - remote, hybrid, or whatever helps you do your best work - A competitive salary with a benefits package to match - Room to grow your career within a fast-growing international design