This is us

At Avenga, we believe that human creativity empowers technology that matters. Operating globally, our 6000+ specialists provide a full spectrum of services, including business and tech advisory, enterprise solutions, CX, UX and Ul design, managed services, product development, and software development.

This is the job

We are looking for Middle Java Engineer with strong knowledge in Java and Kotlin, available for minimum 50%. The goal is to build a unified, scalable ads platform.

We are transforming a long-standing business application into a modern technology stack. Our goal is to build a modular monolith designed for scalability and future microservices separation. We follow hexagonal architecture and Domain-Driven Design (DDD) principles to ensure clean, maintainable solutions.

This is you

• A Java Developer with strong experience in modern Java (Java 17+, ideally Java 21)
• Experience in modern Kotlin
• Skilled in working with REST APIs
• Knowledge of relational databases (PostgreSQL preferred) and non-relational databases (MongoDB preferred)
• Ability to work with diverse API authentication workflows (API keys, OAuth tokens)
• Strong cloud development skills (any cloud, GCP preferred)
• Experience with Docker; Kubernetes knowledge is a plus
• Experience building scalable, high-performance services in a cloud environment
• Experience with ETL processes, large data volumes, and reporting
• Familiarity with tools used on the project: Kafka, BigQuery, Spark, Dataflow
• AdTech background
• English: Upper-Intermediate

Nice to have

• Experience with DSP solutions
• Knowledge of hexagonal architecture and Domain-Driven Design
• Experience working with legacy code and performing structured refactoring
• Ability to write clean, testable code (SOLID, clean code, unit & integration tests)
• Strong communication skills and readiness to propose improvements
• Ability to collaborate with a cross-functional team and share knowledge

This is your role

• Developing backend features using a modern technology stack: Java 21, Spring Boot 3.4, Hibernate, Microsoft SQL Server, Elasticsearch, Docker, OpenAPI, Modular monolith architecture (early stage), moving toward microservices
• Working with legacy code and performing meaningful refactorin
• Writing readable, maintainable, testable code
• Creating unit and integration tests
• Collaborating with the front-end team to define and evolve API contracts
• Participating in architectural discussions and suggesting improvements
• Working within a backend team (currently 4 developers), sharing knowledge, and taking responsibility for solutions

At Avenga, everyone matters. We provide equal opportunities in recruitment, career development, and leadership, regardless of race, ethnicity, gender identity, sexual orientation, disability, age, religion, or any other characteristic. We are committed to fostering a work environment where our diverse community of employees, candidates, and business partners actively shapes our growth. By bringing together people from different backgrounds and experiences, we build a workplace where everyone feels free to be themselves while honoring the boundaries of others.