(Senior) Backend Engineer – Golang

7NXT GmbH; Berlin; Hybride; EUR 90 000 - 120 000; Plein temps

Avantages offerts par ce poste

Hybrid working model

Urban Sports Club membership

Nilo Health access

Wellbeing apps: 7Mind, Gymondo & Buddy

Navit mobility budget

Annual training budget

Childcare support

Pet-friendly office

Résumé du poste

Gymondo in Berlin is seeking a (Senior) Backend Engineer to build and evolve scalable backend services powering our platform for hundreds of thousands of users. You will work with a modern tech stack, implement clean architecture, and translate legacy ideas into maintainable code that supports growth, reliability and efficiency.

You will design REST APIs, contribute to microservices, and build automated infrastructure using AWS, Kubernetes and Terraform.

Qualifications

• 4+ years of backend-focused development including infrastructure
• 3+ years in microservices with reliability, scaling, stateless apps, event-driven systems
• 3+ years designing REST APIs with OpenAPI standards
• Hands-on Golang and Gin-Gonic experience
• Proven coding practices: peer code reviews, unit testing and agile development
• Fluent English

Responsabilités

• Build, improve and maintain scalable backend services with Golang and Gin-Gonic
• Design REST APIs following OpenAPI standards for clarity and maintainability
• Contribute to microservice architecture focusing on reliability and scale
• Refactor legacy concepts into clean, reusable patterns
• Develop data-driven features from design to deployment
• Work with AWS, Kubernetes and Terraform for scalable infra
• Participate in peer reviews, write unit tests and advocate Agile
• Share knowledge and grow with the team

Connaissances

Golang

Gin-Gonic

Microservices

REST APIs

OpenAPI

AWS

Kubernetes

Terraform

Unit testing

English fluent

Outils

Docker

Kubernetes

Terraform

Description du poste

The essentials Team: 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 impact

As (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 drive

• You 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 you

Must-have

• 4+ 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-have

• Experience 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 stack

Golang, Kotlin, Node.js, Java 17 Gin-Gonic, Ktor, NestJS, Spring Boot Elasticsearch, MySQL, PostgreSQL, DynamoDB, MongoDB, Redis Terraform, Docker, Kubernetes Event-Driven Architecture AWS

Benefits Success 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 welcome!

These benefits apply to full-time and part-time permanent employees. Working students and interns receive a pro-rated selection.

People who make things happen

Gymondo is one of the leading digital fitness and nutrition platforms in the DACH region — with over 2,000 workouts, holistic training programmes and smart nutrition plans. As part of 7NXT Health Group, we help millions of people make movement a lasting part of their everyday lives. Our team pushes each other, thinks critically and grows together. We take responsibility — for our users, our products and our planet.

Everyone counts

We welcome what makes you unique. At Gymondo we believe in diversity, openness and team spirit. No matter which gender you identify with, whether you have a disability, what your neurotype is, where you come from, what you believe in or how you love — you are welcome here.

Don’t meet all the criteria? No problem — if you’d like to help shape the future of fitness & wellbeing with us, we look forward to your application.

Need a more accessible process or have questions? Write to us — we’ll find a way.

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