SmallGiants is an award-winning digital marketing agency and product studio working at the intersection of brand, growth, and AI.

We help ambitious companies scale by combining strategy, design, and performance marketing and we’re now building AI-powered marketing platforms that redefine how modern marketing teams operate. Our work spans early-stage startups through to global enterprises, with a strong focus on experimentation, measurable impact, and high-quality execution.

If you enjoy building robust systems that power real-world products, and want to be part of a team shaping the future of AI-driven marketing, this role is for you.

We’re looking for a Senior Backend Developer to design, build, and maintain scalable backend services that power our internal platforms and client-facing AI products.

You’ll be responsible for building clean, reliable APIs, shaping backend architecture, and ensuring performance, security, and maintainability at scale. This is a hands-on role with real ownership and influence over technical direction.

• Design and build RESTful APIs using Fastify and TypeScript
• Apply Test-Driven Development (TDD) to deliver reliable, well-tested systems
• Design and integrate data models using Supabase (Postgres, Auth, Storage)
• Build scalable, production-ready services deployed on AWS
• Write clean, maintainable, and well-documented code
• Collaborate on system design, performance optimisation, and security best practices
• Work closely with product, frontend, and AI teams to deliver end-to-end solutions

Required

• Strong experience with TypeScript and Node.js
• Proven experience building APIs with Fastify (or similar frameworks)
• Solid understanding of TDD and automated testing
• Experience with AWS and containerised environments (Docker)
• Hands-on experience with Supabase or Postgres-based backends
• Comfortable working with Git and CI/CD pipelines

Nice to Have

• Experience with OpenAPI / Swagger documentation
• Strong SQL skills and database optimisation experience
• Familiarity with AI agents, LLM integrations, or AI-enabled systems
• Experience with serverless architectures and Infrastructure as Code (e.g. Terraform)

• Work on AI-powered products, not just client projects
• High ownership and influence over technical decisions
• Small, senior team with high standards and low bureaucracy
• Real-world impact, systems you build will be used daily
• Flexible working and a culture that values clarity, quality, and curiosity