Senior Backend Engineer, Python/Django (f/d/m): Path to CTO

Berlin, 35-40 hours per week, starting immediatly Do you want to work and help shape the world of work? Then join us and become part of a purpose-driven team working towards a fair and sustainable world of work. We are INES Analytics – a passionate software start-up in the heart of Berlin. Our mission: to make social sustainability measurable and to support companies in creating fair working conditions. To drive our mission forward, we’re looking for you: a committed individual to strengthen our team. A growing team, a clear mission and the chance to help shape real social change through your work – data-driven, practical and forward-looking. Tasks You'll own the backend technically and be the go-to person for architecture and infrastructure. You'll write code yourself, help the team grow, and set the technical direction. Together with us, you'll grow into the CTO role. In Detail: Own the backend (Python/Django): architecture, code quality, scalability and maintainability Design and evolve REST APIs and integrate external systems Build authentication and SSO (e.g. OAuth2, OpenID Connect, SAML) Design and run asynchronous processing and background jobs Keep the system fast and scalable as we grow: profiling, query optimization, caching Build a strong testing culture with automated unit, integration and end-to-end tests Review code and pull requests, and set shared engineering standards Mentor junior developers and support their growth Shape and improve reliable deployment, release and CI/CD processes Run and optimize our cloud infrastructure on AWS, containerized with Docker and managed as Infrastructure as Code Set up monitoring, logging and alerting so issues are caught before customers notice them Write and maintain clear technical documentation on architecture, APIs and runbooks Build security and data protection (GDPR) into our architecture and code Work closely with product, design and founders, and bring technical input to the roadmap Requirements The following qualifications and experiences are required * Experience as a tech lead or in a first leadership role * Several Years of backend development experience with Python and Django Strong PostgreSQL skills (data modeling, performance tuning, migrations) Experience designing and building REST APIs (e.g. Django REST Framework) Hands-on experience with authentication/SSO and integrating external systems Experience with asynchronous task processing A proven track record of improving performance and scaling systems under growing load Solid testing practice (e.g. pytest) and a belief that well-tested code ships faster Confident with Linux, deployment and cloud infrastructure, especially AWS (incl. S3), nginx and Gunicorn Experience with Docker and Infrastructure as Code (e.g. Terraform) Experience with CI/CD pipelines (e.g. GitHub Actions, GitLab CI) Experience with monitoring and observability A good understanding of SaaS architecture, security and data protection You write clear documentation and value it as part of the work Experience with code reviews and a genuine interest in mentoring others Strong communication skills: you can explain technical trade-offs to non-technical people and make decisions together with them A startup mindset: you're pragmatic, take ownership and handle ambiguity and changing priorities well The drive to grow into a leadership role Fluent English and / or German Even if you don’t tick all the boxes perfectly, we’d love to hear from you! Nice to have: Previous startup experience Experience with compliance frameworks (e.g. ISO 27001, SOC 2): Benefits Real ownership and a clear path to CTO A small, motivated team where decisions happen quickly A Job with Purpose: Together with our team, you’ll lay the foundation for a future free of discrimination for all employees in companies Flexible work hours with a portion of mobile work Direct access to the founding team instead of anonymous corporate structures Real responsibility from day