Fullstack Developer (m/f/d)

Expert Systems AG; Berlin; Hybrid; Vertraulich; Vollzeit

Zusammenfassung

A technology solutions company in Berlin is looking for a Backend/Fullstack Developer with 3–5 years of experience in development. You will build scalable backend services and collaborate with product teams. Knowledge of TypeScript, GraphQL, and Kubernetes is essential. This role offers a hybrid work model, modern office, and plenty of opportunities for personal and professional growth.

Leistungen

Flexible working hours

Modern office

Room for ideas

Choice of hardware

Qualifikationen

• 3–5 years of experience in backend or fullstack development.
• Solid knowledge of TypeScript and JavaScript.
• Experience with GraphQL and/or REST APIs.
• Strong understanding of PostgreSQL.
• Hands-on experience with Kubernetes.
• Familiarity with CI/CD workflows and Git.
• Good English skills; German is a plus.

Aufgaben

• Develop and maintain backend services.
• Build and optimize frontends using React.
• Design and maintain APIs.
• Implement secure authentication flows.
• Collaborate with cross-functional teams.

Kenntnisse

Backend or fullstack development

TypeScript

Kubernetes

GraphQL

PostgreSQL

CI/CD workflows

Unix shell

Team collaboration

Good English skills

Tools

NestJS

Node.js

TypeORM

Jobbeschreibung

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 You’ll Do

• Develop and maintain scalable backend services with NestJS, Node.js, 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 reviews, best practices, and knowledge sharing within the team.

Requirements

Your Profile

• 3–5 years of experience in backend or fullstack 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 containerized 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, Monsum, 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