Senior Backend Engineer

About SportCity

At SportCity, we are transforming the fitness industry by seamlessly integrating our physical gym facilities with innovative digital solutions.

Our core application, Electrolyte, serves as the backbone of our digital ecosystem, connecting our mobile apps, website, and third-party services. Built on Ruby on Rails, Electrolyte acts as middleware, enabling seamless communication between our Gym Management system and internal and external platforms.

The Role

We’re looking for a Senior Backend Engineer with 7+ years of experience in backend development to join our Digital Product & Engineering team. You’ll play a key role in maintaining and improving Electrolyte, ensuring reliability, scalability, and seamless integrations that directly impact our members and internal operations.

This is a hands-on role that requires a balance of technical expertise, problem-solving skills, and a commitment to delivering high-quality solutions.

What else you will do

• Design and Development: Build and enhance Electrolyte’s backend services to meet business needs and improve system efficiency.

• Feature Implementation: Develop new features and optimize existing functionality to support our mobile apps, website, and integrations.

• System Integration: Ensure smooth communication between Electrolyte, our Gym Management system, and other third-party services.

• Code Quality: Write clean, maintainable, and efficient code, backed by automated tests to ensure reliability and long-term maintainability.

• Troubleshooting: Identify and resolve complex issues, ensuring high availability and performance of the middleware.

• Collaboration: Work closely with frontend developers, product managers, and other stakeholders to deliver seamless solutions that enhance the user experience.

About You

Experience & Skills:

• 7+ years of professional experience in backend development, with at least 5 years using Ruby on Rails.

• Deep knowledge of PostgreSQL, with experience in designing and optimizing databases.

• Proven expertise in API development and integration (RESTful APIs).

• Solid experience with GitHub and CI/CD pipelines.

• Familiarity with frontend integration (HTML, CSS, JavaScript) to support seamless interactions.

• Strong focus on writing clean, maintainable, and well-documented code.

• Experience troubleshooting and resolving performance issues in a production environment.

Personal Attributes:

• Proactive problem-solver with a detail-oriented mindset.

• Strong communication skills in English; Dutch is a plus.

• Self-motivated, collaborative, and eager to contribute to a high-performing team.

• Able to work at least 3 days per week in our Amsterdam office.

Technologies We Use

• Backend: Ruby on Rails (latest version), PostgreSQL, Redis

• Tools & DevOps: GitHub (CI/CD), Heroku, AppSignal (Monitoring)

• Frontend Integration: HTML (Slim), CSS (Bootstrap), JavaScript (Stimulus, esbuild)

• Testing: RSpec (mostly request and system tests)

• APIs: RESTful APIs

Hi, we are SportCity

We stand for more movement and are your neighborhood sports club.

Every day, we work with over 2,500 colleagues to bring 'more sport to your City'. And we do this not only from our clubs, but also from our Service Office in Amsterdam-Zuidoost.

The welcoming and open atmosphere you feel in our clubs is just as present at our Service Office. We are a young, dynamic, and energetic organization, and happy members and colleagues are our biggest motivation. So, a quick game of table tennis or squash in between? Why not! Not really into sports? No worries!

Where movement and club spirit come together, working feels like coming home.

What do we offer you?

• 💸 Attractive salary and benefits package tailored to your experience;

• 😊 an open and friendly company culture, where everyone is equal in a sporty and young organization;

• ✈️ 25 vacation days per year, 8% holiday allowance, and pension accrual;

• 🏋️ the opportunity to work out in more than 100 SportCity clubs;

• 🚗 free parking, but also within walking distance of Holendrecht station;

• 🚍 travel allowance;

• 💻 of course, a laptop and ESIM from us;

• 🍎 fresh fruit or other snacks at the office;

• 🏠 the possibility to work from home for two days a week.

Ready to join our team?

Does this challenge sound like a perfect match for you? Then don't wait any longer and apply directly! We can't wait to meet you and work together on an online experience that inspires and activates.