Fullstack Developer (m / f / d)

At Proven Expert we believe that trust is the most important currency in business. Since 2011 we have been building a platform that now enables more than 1.1 million service providers, freelancers and companies to make authentic customer feedback visible and become more successful. Our tools help to use reviews in a targeted way for better visibility in SEO and social media as well as for a strong online reputation.

Our headquarters are in Berlin with another office in Madrid. Our team is just as international as our customers. We work together across borders both digitally and on‑site always with the shared goal of making trust tangible and usable online.

What you can look forward to: Every idea counts with us. We are a team that values initiative.

Tasks

What Youll Do

• Develop and maintain scalable backend services with NestJS, TypeScript and TypeORM.
• Build and optimize JS/React frontends that deliver great user experiences.
• Design and maintain GraphQL (Apollo) and REST APIs used across teams and products.
• Work with Kubernetes in production environments (OVH, AWS or GCP).
• Implement secure authentication and authorization flows with Keycloak.
• Write clean, well‑tested code and contribute to automated testing (unit, integration, E2E).
• Collaborate with Product Design and Business teams to bring ideas to life.
• Contribute to code‑review best practices and knowledge sharing within the team.

Requirements

Your Profile

• 35 years of experience in backend or full‑stack development.
• Solid knowledge of TypeScript and JS (NestJS & TypeORM experience a plus).
• Experience working with GraphQL and / or REST APIs.
• Strong understanding of PostgreSQL (MongoDB exposure is a plus).
• Hands‑on experience with Kubernetes and containerised environments.
• Familiarity with CI / CD workflows and Git (Bitbucket branching PR reviews).
• Comfortable with Unix shells (bash / zsh).
• Good English skills; German is a plus.
• A collaborative team player with a passion for learning and sharing knowledge.

Nice to Have

• Experience with HubSpot, SendGrid, Bevo or Maxio.
• Knowledge of Kafka or RabbitMQ.
• Extra skills in PHP / Symfony, Golang, Python or Rust.
• Curiosity about AI developer tools (e.g. GitHub Copilot, Anthropic Claude).

Benefits

• An open international team with real opportunities for development.
• Flexible working hours.
• Modern office in Berlin with the option to work from home (hybrid work model).
• Plenty of room for ideas and the chance to actively shape the future of our platform.
• Free choice of hardware and modern tools for efficient work.

Join Our Journey

At Proven Expert we believe in the power of diversity. Our team is made up of talented individuals from different backgrounds, cultures and perspectives. We value the uniqueness of every team member and foster an inclusive work environment where innovation and creativity can thrive. With us every voice counts. We welcome applications from people of all genders, ethnic backgrounds, religions, sexual orientations and abilities.

Ready to shape the future of online reputation management with us.

Apply now and join our team.

Key Skills

Children Activity, Accounts Assistant Credit Control, Android, Apparel Merchandising, Franchise, Construction Equipment

Employment Type: Full Time

Vacancy: 1