Senior Full-Stack Developer

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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.

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

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.

• 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)

• 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

• This is a fully remote role
• Your line manager is the Technical Lead
• You will work in the Engineering Team

• 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