(Senior) Backend Engineer – Golang

The essentialsTeam: Product & Engineering Start date: As soon as possible Location: Berlin — hybrid, 3 days in the office Working language: English (German: a plus) Salary band: Shared before your first interview Your impactAs (Senior) Backend Engineer at Gymondo, you build and improve the scalable backend systems that power our platform for hundreds of thousands of active users. You work with a modern tech stack, establish new services using clean architecture principles, and help translate legacy concepts into maintainable, future-proof code. Your work directly shapes the technical foundation that enables Gymondo to grow — reliably, efficiently and at scale. What you’ll driveYou build, improve and maintain scalable backend services using Golang and Gin-Gonic, following clean architecture and established design patterns You design and implement REST APIs following OpenAPI standards, with a focus on clarity, reliability and long-term maintainability You contribute to our microservice architecture — working on reliability, scaling, stateless applications and event-driven systems You rebuild legacy concepts and translate them into well-known programming patterns with transparent and maintainable business logic You develop data-driven features and are involved in all stages of the development process — from design to deployment You work on our scalable, automated infrastructure using AWS, Kubernetes and Terraform You participate in peer code reviews, write unit tests and champion agile development practices You share knowledge, discuss better solutions openly and grow together with the team What defines youMust-have4+ years of professional experience in backend-focused development, including infrastructure 3+ years contributing to microservice architectures with a focus on reliability, scaling, stateless applications, event-driven systems and clean architecture 3+ years designing REST APIs following OpenAPI standards Proven hands-on experience with Golang and Gin-Gonic Ability to design proof of concepts and prototypes Standardised coding practices: peer code reviews, unit testing and a preference for agile development An open mindset and genuine interest in state-of-the-art technologies and methodologies Fluent English Nice-to-haveExperience with JVM languages (Kotlin / Java) and frameworks such as Ktor, Spring or Node.js A Product Engineer mindset: balancing technical excellence with business impact, proactively identifying trade-offs that prioritise user value and speed-to-market without compromising long-term system health Strong communication skills across the Product & Engineering team and additional stakeholders A collaborative, humble approach — you promote good relationships in your guild and are always willing to learn from others Our tech stackGolang, Kotlin, Node.js, Java 17 · Gin-Gonic, Ktor, NestJS, Spring Boot · Elasticsearch, MySQL, PostgreSQL, DynamoDB, MongoDB, Redis · Terraform, Docker, Kubernetes · Event-Driven Architecture · AWS BenefitsSuccess requires positive energy. That's why we ensure the right conditions are in place — physically, mentally, and within the team: 🏖️ 30 days of vacation per year + Christmas Eve & New Year's Eve as additional paid days off 🏠 Hybrid working model — 60% in the office, 40% from home, applicable to all working hours 🌍 Up to 4 weeks of work from abroad per year (Berlin-based roles) 🏋️ Free Urban Sports Club M membership & access to Nilo Health for mental health and personal development 📱 Free access to 7Mind, Gymondo & Buddyfit — our own digital wellbeing products 🚲 €30 monthly mobility budget via Navit 📚 €1,000 annual training budget + a wide range of opportunities for personal growth and development 👨👩👧 Family-friendly benefits — childcare costs & paid sick days for children 🍎 The office classics — fruit & vegetable basket, muesli & yogurt (also vegan), drinks & snacks 🐶 Pet-friendly office — four-legged colleagues are very wel