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 Lead Java Developer to provide technical leadership across payment-platform development. You will work closely with Architects, Senior Developers, Product, Business, DevOps, Security, and AI teams to define technical solutions and drive successful implementation.

Key Responsibilities

• Lead the design and development of high-scale, secure, resilient payment platforms and APIs using Java 18–25 and Spring.

• Define and review application architecture, technical designs, API standards, coding standards, and engineering best practices.

• Lead design decisions across microservices, distributed systems, event-driven architecture, caching, database, and integration layers.

• Design high-performance solutions using PostgreSQL, MySQL, Hibernate/JPA, Redis, Kafka, and RabbitMQ.

• Establish secure authentication and authorization using JWT, OAuth 2.0/2.1, OpenID Connect, and modern API-security practices.

• Lead implementation of cryptographic algorithms, digital signatures, hashing, encryption, and secure payment-data protection.

• Drive OWASP, threat modelling, secure coding, and security-by-design practices.

• Lead technical feasibility studies and evaluate emerging technologies and architecture alternatives.

• Own complex production incidents, performance issues, scalability challenges, and cross-platform root-cause analysis.

• Drive refactoring, modernization, automation, reliability, observability, and performance initiatives.

• Establish testing strategies covering JUnit, Mockito, functional, integration, API, and automated testing.

• Lead build and release engineering using Maven, Gradle, multi-module builds, dependency management, Nexus, and CI/CD.

• Guide containerized and cloud-based application development and deployment.

• Conduct architecture and code reviews and ensure implementation quality across teams.

• Mentor Senior and Junior Developers and create a strong engineering culture.

• Collaborate with Architects and business stakeholders to balance business value, technical risk, scalability, security, and delivery timelines.

• Lead technical brainstorming and continuously identify opportunities to improve the product.

• Evaluate and promote appropriate AI technologies and AI-assisted engineering practices to improve development, automation, testing, and operational efficiency.

• Represent the development team in technical discussions and contribute to organizational engineering standards and governance.

Qualifications & Experience

Java 18–25 • Spring/Spring Boot • System Design • Distributed Systems • REST/API Design • Hibernate/JPA • PostgreSQL • MySQL • Redis • Kafka • RabbitMQ • JWT • OAuth 2.0/2.1 • OpenID Connect • Authentication • Authorization • API Security • Cryptographic Algorithms • OWASP • Maven • Gradle • Nexus • JUnit • Mockito • Git/GitHub • CI/CD • Docker • Cloud • Agile/Scrum/Kanban

Required Skills

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

• 7–10 years of professional Java development experience.

• Proven experience designing and delivering enterprise-scale applications.

• Strong architecture, system-design, security, performance, and troubleshooting skills.

• Experience leading technical initiatives and mentoring developers.

• Excellent communication and stakeholder-management skills.

• Ability to translate business requirements into scalable technical solutions.

• Payment/FinTech experience is strongly preferred.

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.