Sr. Full-Stack Developer

About TRX Training

As a leader in functional fitness, TRX is renowned for pioneering Suspension Training and delivering world‑class training tools and experiences—from hardware to digital education, live and on‑demand workouts, and premium mobile and web applications. TRX empowers trainers and fitness enthusiasts with powerful, accessible training solutions across platforms and locations.

We’re looking for a talented Full‑Stack Engineer to join our tech team, crafting exceptional digital experiences that support TRX’s e‑commerce, education, and content platforms. Using modern stacks—from Next.js and Shopify to serverless AWS and Firebase—you’ll help scale our digital products, enabling more users globally to move better, feel better, and live better.

• Develop and maintain TRX’s primary web applications (Shopify storefront, marketing pages, content portals) using Next.js, React, SCSS Modules, and Shopify + Liquid.
• Implement custom Shopify APIs, including Shopify Functions, UI Extensions, and Custom Pixels, enhancing product discoverability and performance.
• Build serverless backend services using Python (Flask / FastAPI), AWS Lambdas, and appropriate infrastructure, supporting APIs, webhooks, and integrations.
• Design and manage data layers using Firebase, Postgre
  
  SQL, and Graph
  
  QL—fostering efficient data flow across apps and backend systems.
• Integrate with payment and subscription platforms such as Stripe, Recharge, and Revenue Cat to power e‑commerce, in‑app purchases, and recurring revenue.
• Implement feature management and experimentation using Unleash (A/B testing), enabling data‑driven improvements.
• Monitor and optimise application performance with tools like Data Dog.
• Ship fast via modern CI/CD pipelines (Git Hub Actions, Vercel), with a focus on quality, reliability, and performance.
• Collaborate cross‑functionally with product, design, marketing, and operations teams to rapidly prototype, test, and launch new features.

• Proven experience with Next.js and React, including SCSS Modules or similar CSS‑in‑JS workflows.
• Hands‑on with Shopify development: theme templating (Liquid), Shopify Functions, UI Extensions, Custom Pixels.
• Backend development in Python (Flask or FastAPI) and familiarity with serverless architecture on AWS (including Lambdas).
• Experience working with Firebase, Postgre
  
  SQL, and Graph
  
  QL for data modelling and APIs.
• Integration knowledge of Stripe, Recharge, Revenue Cat, or comparable payment and subscription services.
• Familiar with A/B testing frameworks, e.g. Unleash, and performance monitoring via Data Dog.
• Comfortable with CI/CD pipelines, Git workflows, and deployment tools like Git Hub Actions and Vercel.
• Strong in debugging, testing (unit, integration, E2), and performance optimisation.
• Excellent collaboration, communication skills, agile mindset, and customer‑first approach.
• (Bonus) Experience with digital education platforms, fitness or wellness products, and scalable consumer apps.

• Experience developing or maintaining fitness‑related platforms (e.g. workout apps, live and on‑demand class systems).
• Familiarity with mobile app backend (especially for TRX App).
• Knowledge of user personalisation, recommendation systems, or content delivery optimisation.
• Understanding of global scale, internationalisation (like localisation), and working in fast‑iterating product environments.

Be part of a globally recognised, dynamic fitness brand that bridges physical hardware and digital innovation. Work on impactful products—apps, e‑commerce, education—that touch fitness professionals and enthusiasts worldwide. Fast‑paced, collaborative culture with autonomy, experimentation, and direct impact. Cutting‑edge stack, modern workflows, and room for professional growth. Competitive compensation and benefits (negotiable).