30 - Senior Software Engineer (Full-Stack, Backend-Heavy)

About the opportunity

Our client is an early-stage European startup building the operating system for class-based gyms and studios: scheduling, lead capture, member management, payments, workforce management, multi-location support, and a branded member app — all in one product. The team is small, moves fast, and is shipping for its first group of launching customers. Engineering is the current bottleneck as the product scales past its early adopters, and that's where you come in.

What you'll build

This role sits where scheduling, payments, memberships, and mobile meet. Concrete areas of work:

• Flexible membership and booking systems that support many different gym business models without custom development for each one

• Integrations with third-party fitness and booking platforms, kept consistent for both gyms and members

• Automation that takes repetitive admin work off gym staff

• The React Native member app: engagement, retention, communication

• A multi-tenant platform serving many organizations with different needs on a clean, maintainable architecture

• Performance, reliability, and developer experience across the platform

No two weeks look the same. Expect to move between product, architecture, and hands-on building.

!!!What matters most for this role

We're specifically looking for backend-heavy full-stack profiles. The complexity that needs an experienced hand sits in:

• Payments logic

• Multi-country and multi-currency handling

• Volume: the platform processes thousands of bookings a month

Frontend work leans on Vue/TypeScript.

Responsibilities

• Own features end to end: discovery, technical design, implementation, deployment

• Design and build flexible systems for evolving gym workflows

• Develop and maintain backend services in PHP and Laravel

• Build frontend experiences in Vue 3 and TypeScript

• Contribute to the React Native mobile app

• Work directly with founders and product on solving customer problems

• Improve architecture, performance, scalability, and maintainability

• Take part in code review and technical discussion

• Touch infrastructure, deployment pipelines, and operational improvements where useful

• Apply AI tooling to speed up both the product and the engineering workflow

Tech stack

• Backend: PHP 8+, Laravel

• Frontend: TypeScript, Vue 3, Vite

• Mobile: React Native

• Database: PostgreSQL

• Cache & queues: Redis

• Infrastructure: AWS, Cloudflare

What we're looking for

• 7+ years of hands-on full-stack experience with a strong backend lean

• Clean, modern PHP/Laravel and Vue/TypeScript

• Comfortable with React Native,

• Able to make autonomous decisions without detailed specs or heavy process

• Cares about shipping value fast without losing sight of scalability

• Applies AI tools to accelerate development, not just talks about it

• Enjoys real-world product complexity: payments, multi-tenant logic, scale

Bonus points

• Domain-Driven Design, Event-Driven Architecture, or Event Sourcing

• Experience building multi-tenant SaaS products

• AWS infrastructure and CI/CD

• Experience integrating external platforms and APIs

• Open-source contributions

• Startup experience

Not a fit if

• You need detailed specs and predefined solutions before you can move

• You want to stick to one layer of the stack

• You need process, planning ceremonies, or steady direction to keep going

• You prefer maintaining existing systems over building new ones

• You're looking for a large org with narrowly specialized roles