Java Software Engineer

Ubique Systems; Kraków; On-site; PLN 180,000 - 280,000; Full time

Job summary

Ubique Systems is seeking a Senior Java Software Engineer to develop reliable, scalable cloud-native applications for digital assets and blockchain projects. The role focuses on Java, RESTful services, Kafka, Kubernetes, Helm, secure development, leadership, and mentoring.

You will support the development team when issues arise and collaborate with stakeholders in English. The ideal candidate will have deep experience with Java-based microservices, modern DevOps practices, and a passion for

Qualifications

• At least 5 years of Java experience.
• Experience building cloud-native distributed systems with RESTful services and Kafka.
• Hands-on Kubernetes and Helm experience.
• Strong security awareness and attention to detail.
• Excellent English communication.

Responsibilities

• Design and develop reliable, scalable cloud-native Java applications.
• Build RESTful services and Kafka-based event-driven solutions.
• Deploy and support applications on Kubernetes using Helm.
• Lead implementations and ensure high-quality, secure code.
• Mentor junior developers and review code.
• Collaborate with stakeholders in English.
• Contribute to Ethereum-based blockchain and digital-asset projects.
• Support the development team in diagnosing application issues.

Skills

Java

RESTful API

Kafka

Kubernetes

Helm

Security

DevOps

Cloud computing

English communication

Tools

Spring Boot

JPA / Hibernate

SQL

Job description

Role Summary: We are seeking a Senior Java Software Engineer to develop reliable, scalable cloud-native applications for digital-assets and blockchain projects. The role focuses on Java, RESTful services, Kafka-based event-driven architecture, Kubernetes, Helm, secure development, implementation leadership, and mentoring, while supporting the development team when application issues occur.

Key Responsibilities

• Design and develop reliable, scalable cloud-native Java applications.
• Build RESTful services and Kafka-based event-driven solutions.
• Deploy and support applications on Kubernetes using Helm.
• Lead implementations and contribute to secure, high-quality code.
• Support the development team in diagnosing and resolving application issues.
• Mentor junior developers and provide code-review feedback.
• Contribute to blockchain and digital-asset solutions, particularly Ethereum-related projects.
• Collaborate with technology and business stakeholders in English.
• Java: At least 5 years of experience in Java.
• Cloud-Native Distributed Systems: Expertise in developing cloud-native applications for distributed systems using RESTful web services and Kafka-based event-driven architectures.
• Kubernetes and Helm: Hands-on experience with Kubernetes and Helm.
• Security: Strong attention to detail and security awareness.
• Technology Trends: Interest in cloud computing, DevOps practices, blockchain technologies, and digital assets.
• Communication: Excellent communication skills and the ability to interact effectively with colleagues in English.

Preferred Skills - Good to Have

• Engineering Leadership: Ability to lead implementations, conduct code reviews, and mentor junior developers.
• Blockchain and DLT: Experience contributing to distributed-ledger projects, particularly Ethereum-based solutions.
• Digital Assets: Understanding of tokenization or digital-asset platforms.
• Spring Boot: Experience with Spring Boot and related Spring components.
• Data and Persistence: Experience with JPA or Hibernate, SQL, and relational databases.
• Automated Testing: Experience with JUnit, Mockito, and integration testing.

Additional Skills - Optional

• Observability: Familiarity with application logging, metrics, and tracing tools.
• API and Platform Security: Familiarity with authentication, authorization, certificates, and secrets management.
• Smart Contracts and Web3: Familiarity with Solidity, Web3 libraries, or blockchain integration patterns.
• NoSQL and Caching: Familiarity with MongoDB, Redis, or another non-relational data platform.
• Reactive Programming: Familiarity with Spring WebFlux or Project Reactor.
• AI-Assisted Development: Familiarity with tools such as GitHub Copilot.
• Certifications: A relevant Java, Spring, cloud, Kubernetes, or blockchain certification.