Fullstack Developer - Backend Focus / Remote within Germany (all genders)

We are looking for a Fullstack Engineer whose primary strength lies in backend engineering, but who is also comfortable implementing production-ready frontend features. 
Most of your technical depth will be applied on the backend, but feature ownership does not stop at the API boundary. You join a small cross-functional product team that works with a Product Owner who sets the why, what and when, while the team owns the how. Our technology stack is a containerized PHP/Symfony microservices backend running on AWS infrastructure managed through Terraform, and an Angular frontend. We practise continuous delivery, so your work reaches production quickly and is covered by automated end-to-end tests.

You will 

• Own features end-to-end, from architecture, data model and backend implementation to frontend, deployment and production support
• Design, build and operate container-based backend services, APIs and infrastructure in AWS
• Design solutions for distributed, message-driven and service-oriented systems
• Implement the frontend part of your features in Angular based on product requirements and designs
• Analyse business requirements and translate them into pragmatic technical solutions, and continuously improve the performance, reliability and maintainability of existing applications
• Write clean, maintainable and understandable code with appropriate automated tests; conduct thorough code reviews and contribute to engineering standards
• Troubleshoot and debug issues across backend, frontend and infrastructure
• Collaborate closely with product, design and other engineers in an agile environment
• Use AI coding assistants and agents as a regular part of your engineering workflow: break engineering work down so that it can be delegated effectively to AI agents, and critically review AI-generated code with the same standards as human-written code

You have 

• 5+ years of professional software development experience, with the majority of your experience focused on backend engineering
• Strong professional experience with PHP and Symfony or with another backend ecosystem such as Java, Python or Node.js and the willingness to work in PHP/Symfony from day one
• In-depth understanding of REST APIs, message-based systems, microservice architectures and distributed systems
• Strong experience with relational databases, data modeling and schema design
• Hands-on professional experience implementing frontend features in Angular or a comparable framework such as React or Vue.js; strong in component and state logic and API integration; solid enough in styling to implement a given design. 
• Experience with automated testing, Docker and containerized applications, and cloud-native development, ideally hands-on with AWS
• Experience using AI coding assistants or agents such as Claude Code, Cursor, or GitHub Copilot
• Clear communication in English, our working language, and a collaborative engineering mindset; German is a plus

Bonus points for

• Experience with NoSQL systems
• CI/CD pipeline design, Infrastructure as Code (Terraform or CloudFormation) and serverless architectures
• Domain-Driven Design
• LLM-based application development, including RAG, tool/function calling, MCP servers, or agent orchestration
• Component libraries, design systems, and frontend performance optimization
• AWS certifications

• Inclusive, multinational team with 18+ nationalities. English is our company language
• Remote-first within Germany; hybrid-friendly with a modern office in Mainz (open spaces, coffee bar, meeting pods)
• Flexible working hours. We trust you to deliver results, wherever and whenever you work
• Low-hierarchy, open-feedback culture where your voice shapes strategy
• Radical transparency: smart minds collide, great ideas happen
• Real ownership: you ship features end-to-end and see them in production
• AI coding tools as a standard part of the engineering workflow
• Fully paid company workation every year
• Learning & development budget: conferences, certifications, and language courses
• 50 € hrmony voucher: sports, takeout, shopping, your call
• Hardware of your choice
• Competitive salary plus performance-based bonus
• Direct impact on the circular battery ecosystem, helping close the loop on used EV batteries

At Circunomics, we are building the B2B marketplace and data platform for the battery lifecycle: trading first-life, surplus, and second-life batteries, battery analytics, and the digital battery passport. As a green technology and sustainability startup, we use modern software and data-driven insights to keep batteries in use longer, minimize waste, and help accelerate the transition to a sustainable energy future.

Next Mobility Labs is a venture studio building and scaling innovative companies in the mobility, energy, and technology sectors. We partner with founders and industry experts to develop ideas into market-ready businesses. This role is part of one of our latest ventures – conceived and backed by Next Mobility Labs – offering you the opportunity to shape a start-up from the ground up with the resources of an experienced venture studio behind you.