Senior Java Developer (m/w/d) – Quarkus, GraalVM & API-Integration

Berlin

Full or part-time

Permanent employee

Your mission

You will:

Further develop the XP-Layer and take new features from idea to production.
Connect CMS APIs, such as Stibo DX CUE, Livingdocs, CoreMedia, Strapi, or WordPress, via REST, GraphQL, or XML web services.
Transform heterogeneous data models into our generic JSON format for frontends.
Use GraalVM for polyglot development with JavaScript/TypeScript, for example for flexible, customer-specific transformations.
Push forward Native Images with Quarkus and GraalVM so our services start faster and use fewer resources.
Work directly with our customers and their development teams on integration projects.
Bring AI and agentic approaches into our products, such as LLM-powered features or interfaces for AI agents.

Your skills

Must have

Several years of experience in backend development with Java
Solid hands-on experience with Quarkus (required)
Experience with CMS APIs and integrating external systems via REST, GraphQL, or XML
Confident handling of data transformation and mapping between different data models
Experience with containers and Kubernetes, ideally on AWS
Enjoy working with customers and external development teams
Good German skills, spoken and written (native level not required), as well as good English

Nice to have

Experience with GraalVM, especially polyglot with JavaScript/TypeScript
Experience with Native Images in Quarkus or GraalVM
Hands-on projects with Stibo DX CUE, Livingdocs, CoreMedia, Strapi, or WordPress
Initial experience with LLM integrations, AI agents, or agentic development workflows
Background in the media or publishing industry

Our offer

Our Stack
Java · Quarkus · GraalVM · REST · GraphQL · Kubernetes · AWS (incl. Redshift) · React (orchestration UI)

What we offer

A gross annual salary of €60,000–75,000, depending on experience
Full-time, 40 hours per week, with 29 days of vacation
Permanent employment contract
A team that works closely together in the Berlin office, with short communication paths and fast decisions
Products used by millions of people every day
Real room to shape new topics such as GraalVM, Native Images, and AWS

Work-life balance: Compatibility of family and career (we offer a very flexible working environment and try to make everything possible), Deutschlandticket (public transport pass), modern office in a central location, drinks and snacks

About us

ethinking GmbH is a young company based in the heart of Berlin.

We implement new digital business models, platforms, mobile applications, and websites and support our partners and customers with strategic advice, project planning, conception and design through to technical implementation. Our customer portfolio includes RTL (n-tv.de, rtl.de), RTL Radio, DER SPIEGEL, Süddeutsche Zeitung, Swisscom and OEM from Mexiko

We are looking for you – follow the path to success with our team.

We are never bored - we have exciting, complex customer projects! And since many of our customers are early adopters, we work with cutting-edge technologies.

We make our own decisions - no venture capital, no outside decisions!

We believe in work-life balance and have a sense of family - we like to work together and do something together, but we don't have compulsive 'BEER and FOOTBALL' after 6 p.m.!

We are only strong together - independence and commitment to the team count for us

We are well prepared to get to know you:

The application process is completely digitized. Job interviews and introductory appointments will take place online until further notice. In addition, our recruiting team will support you with advice and action in the event of technical challenges within the application process.

And we are also well prepared for the time after you have been successfully hired: Digital induction, online training, and support with work from the mobile office are a matter of course for us during the COVID19 crisis.