Middle/Senior Java Developer

Company Description

Are you passionate about building scalable backend systems that operate under real production load? We are looking for a Middle/Senior Java Backend Developer to join a long-term onsite project in Malmö, Sweden, focused on privacy-sensitive distributed services used at global scale.

You will join a small, autonomous engineering team where ownership, technical excellence, and collaboration are highly valued. The role involves full-cycle development, from architecture discussions and implementation to deployment and production support.

We at Sigma Software offer the opportunity to work on technically challenging products in an engineering-driven environment with modern technologies, high-quality standards, and long-term project stability.

CUSTOMER

Our Customer is a global technology company operating in the consumer electronics and digital services domain. The company develops large-scale platforms and infrastructure used by millions of users worldwide, with a strong focus on privacy, reliability, and seamless user experience.

PROJECT

The project focuses on developing and supporting large-scale backend services operating in a privacy-sensitive environment under high production load. The team designs and maintains distributed systems with strict requirements for reliability, scalability, security, and performance. Engineers work in cross-functional teams and contribute to the entire software development lifecycle.

Job Description

Design, develop, and maintain scalable Java backend services and internal frameworksParticipate in architecture discussions and contribute to technical solution designBuild and support customer-facing services with a focus on reliability, availability, security, and performanceInvestigate and resolve complex production issues related to concurrency and distributed systemsWork with authentication, authorization, caching, data storage, and service integrationsCollaborate with multiple engineering teams and coordinate technical dependenciesParticipate in code reviews, automated testing, CI/CD processes, and release activitiesPrepare technical documentation and communicate technical decisions to stakeholdersTake end-to-end ownership of features and technical solutions from concept to production

4+ years of commercial experience in Java backend developmentStrong hands-on experience with Java and distributed systemsDeep understanding of Java internals, including the Java Memory Model, garbage collection, concurrency, and multithreadingExperience debugging production issues in high-load environmentsStrong knowledge of distributed systems concepts, including consistency, reliability, partitioning, and failure handlingExperience building and scaling customer-facing backend servicesExperience with authentication and authorization mechanismsHands-on experience with Cassandra, Redis, Memcached, or similar technologiesExperience developing REST-based services using Netty or similar frameworksExperience with CI/CD pipelines and automated testingStrong analytical and problem-solving skillsUpper-Intermediate or higher level of English

WILL BE A PLUS

Knowledge of cryptography standards and protocols such as PKCS, KMIP, X.509, AES, KDF, and CAExperience working with security- and privacy-sensitive systemsFamiliarity with machine learning systems or algorithmsExperience with GitHubExperience with Maven, Docker, Kubernetes, Spinnaker, or similar tools

Additional Information

PERSONAL PROFILE

Strong sense of ownership and accountabilityAbility to work independently in autonomous engineering teamsAnalytical and problem-solving mindsetAttention to detail and engineering qualityStrong communication and collaboration skillsAbility to work effectively in complex distributed environments