7NXT GmbH
(Senior) Backend Engineer – Golang
- Compensation
- Not disclosed
- Location
- Berlin
- Work setup
- Hybrid
- Seniority
- Senior
- Employment
- Part time
- Experience
- 3+ years
- Category
- Backend
- Posted
Skills
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
- 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
Full description
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