Senior Java Backend Engineer

Job description

We are seeking an experienced Senior Java Backend Engineer to join our dynamic team in Malmö, Sweden. This role demands deep expertise in Java and a strong background in building and scaling customer-facing web services. The ideal candidate will have significant production experience, a robust understanding of distributed systems, and familiarity with various data storage and caching technologies. You will be responsible for developing reliable, high-performance services, troubleshooting complex production issues, and contributing to architecture and design decisions in a collaborative environment.

• Develop and maintain scalable, reliable, and high-performance Java backend services
• Collaborate with cross-functional teams to design and implement new features
• Investigate and resolve complex production issues under real-world concurrency and load
• Optimize application performance including tuning garbage collection and allocation pressure
• Read and analyze source code of dependencies to solve problems beyond available documentation
• Implement and enhance authentication, authorization, and spam control mechanisms
• Contribute to the design of distributed systems ensuring robustness and fault tolerance
• Write clear design documents and communicate technical decisions effectively to both technical and non-technical stakeholders
• Participate in CI/CD practices and ensure high-quality automated tests are in place
• Operate primarily on-site in Malmö, maintaining effective communication in English

Basic qualifications

• 5+ years of production experience in backend Java development
• Deep understanding of Java memory model, garbage collection, and concurrency utilities
• Experience debugging production issues under real load and concurrency
• Proven expertise in building and scaling customer-facing web services including authentication and authorization
• Strong knowledge of distributed systems concepts such as consistency, partitioning, and failure modes
• Hands-on experience with data storage and caching systems like Cassandra, Redis, or memcached
• Experience writing RESTful services using Netty or similar frameworks
• Proficiency with CI/CD tooling and full automation testing
• Excellent written and verbal communication skills in English

Preferred additional skills, personal traits and experience

• Knowledge of cryptography standards and protocols (PKCS, KMIP, X.509, AES, KDF, CA)
• Familiarity with machine learning systems, frameworks, and algorithms
• Experience with GitHub and build and deployment tools such as Maven, Docker, Spinnaker, and Kubernetes

More information

For more information please contact

Peter Blomsterberg,
+46 730912542
peter.blomsterberg@sigmatechnology.com

• Position

  Senior Java Backend Engineer

• Company

  Sigma Technology Software Solutions

• Location

  Lund, Malmö, Sweden

• Competence area

  Software development embedded systems, System design, System development, Software, Software development, Digitalisation

• Publication date

  2026-08-26

• Expiration date

  2026-09-30

• Contact

  Peter Blomsterberg, peter.blomsterberg@sigmatechnology.com, +46730912542