Java Backend engineer

Ubique Systems; Kraków; Hybrid; PLN 240,000 - 360,000; Full time

Benefits offered by this job

Hybrid work model

Contract employment

Job summary

Ubique Systems in Kraków seeks a Senior Java Software Engineer to build scalable cloud-native Java apps for blockchain-related projects. You will work with Java, REST, Kafka, Kubernetes, and Helm, while mentoring teammates and ensuring secure code quality.

The role emphasizes collaboration with English-speaking stakeholders and a strong focus on cloud computing, DevOps, and distributed systems.

Qualifications

• Senior Java Software Engineer with 5+ years of Java experience.
• Experience building cloud-native Java applications with RESTful services and Kafka-based event-driven architectures.
• Hands-on Kubernetes and Helm experience; secure, high-quality code.

Responsibilities

• Design and develop reliable, scalable cloud-native Java applications.
• Build RESTful services and Kafka-based solutions.
• Deploy and support apps on Kubernetes using Helm.
• Lead implementations and code reviews, mentoring juniors.

Skills

Java

Kafka

REST APIs

Kubernetes

Helm

Security

Cloud-native

English

Tools

Spring Boot

JPA/Hibernate

JUnit

Maven/Gradle

Docker

Git

Job description

We are looking for a Java Backend engineer for one of our customer who has an expertise in:-

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

Employment type:-Contract.

It would be hybrid working within Poland only.

Note:-Only apply if you have valid visa in the EU Region, Sponsorship will not be given.