Fullstack Developer (all genders) - Backend Focus
Your mission
The role
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.
Your profile
You will
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.
The role
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.
Your profile
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
- 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
- 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.