About Kairostek

At Kairostek, we believe great technology starts with great people.

We foster a culture of innovation, collaboration, and continuous growth, empowering our team to make a meaningful impact while building solutions that shape the future. Our teams work across software engineering, artificial intelligence, cloud infrastructure, cybersecurity, digital products, payments technology, and technology operations to deliver scalable and innovative solutions for global organizations.

If you are passionate about technology, problem-solving, and continuous learning, we would love to hear from you.

About the Role

We are looking for a Junior Java Developer to develop and maintain payment APIs and backend services. You will work closely with Senior Developers, Leads, Architects, Product, and Business teams to build secure, scalable, and maintainable solutions.

Key Responsibilities

• Develop and maintain payment applications and REST APIs using Java 18–25 and Spring Framework / Spring Boot.

• Implement clean, maintainable, and reusable code following SOLID principles and design patterns.

• Develop database solutions using PostgreSQL, MySQL, Hibernate/JPA, and Redis.

• Work with Apache Kafka and RabbitMQ for asynchronous and event-driven processing.

• Implement secure APIs using JWT, authentication, authorization, and API-security best practices.

• Apply basic knowledge of cryptographic algorithms, hashing, encryption, and digital signatures.

• Write JUnit, Mockito, functional, and integration tests.

• Use Maven, Gradle, Maven Wrapper, Gradle Wrapper, dependency management, and multi-module builds.

• Work with Nexus Repository and automated build/release processes.

• Participate in CI/CD, Git/GitHub, code reviews, and Agile/Scrum/Kanban practices.

• Investigate defects, production issues, and integration problems and contribute to root-cause analysis.

• Create and maintain technical documentation.

• Collaborate with developers, leads, and architects to improve product quality and engineering practices.

• Explore AI-assisted development tools and emerging technologies to improve productivity and automation.

Required Skills

Java 18–25 • Spring/Spring Boot • REST APIs • Hibernate/JPA • PostgreSQL • MySQL • Redis • Kafka • RabbitMQ • JWT • Authentication & Authorization • API Security • Cryptographic Algorithms • Maven • Gradle • Nexus • JUnit • Mockito • Git • GitHub • CI/CD • Docker • Agile/Scrum/Kanban.

Qualifications & Experience

• Bachelor's degree in Computer Science, Software Engineering, or equivalent experience.

• 2–5 years of Java development experience.

• Strong understanding of Java, OOP, SOLID, REST APIs, and SQL.

• Good problem-solving and debugging skills.

• Strong communication, collaboration, and willingness to learn.

• Payment/FinTech experience is a plus.

What We Offer

• Competitive compensation package.

• Flexible and remote-friendly work environment.

• Professional growth and development opportunities.

• Exposure to international projects and teams.

• Collaborative and inclusive company culture.

• Opportunity to work with modern technologies and innovative solutions.

Equal Opportunity Employer

Kairostek is an equal opportunity employer. We celebrate diversity and are committed to creating an inclusive environment for all employees. We welcome applications from qualified candidates regardless of race, ethnicity, gender, age, disability, religion, sexual orientation, or background.