Mid-Senior Java Software Engineer (Remote - Argentina)

About the role

OKTO is seeking a Mid‑Senior Java Software Engineer to design, develop, and maintain middleware services for its AI‑native payment platform. The role is fully remote and focuses on building scalable, secure microservices that handle millions of financial transactions.

Key responsibilities

• Design, develop and maintain Java‑based middleware applications using Spring, Spring Boot and Spring Cloud.
• Build high‑performance, resilient microservices and RESTful APIs that support payment processing workflows.
• Implement secure authentication and authorization mechanisms such as OAuth2.
• Participate in Agile ceremonies, code reviews and knowledge‑sharing sessions.
• Collaborate with product, architecture, QA, DevOps and security teams to deliver high‑quality software.

Required profile

• Bachelor’s degree in Computer Science, Software Engineering or a related field.
• Minimum 5 years of professional experience developing middleware or backend applications with Java.
• At least 1 year of hands‑on experience with Java 11 or newer.
• Experience in FinTech, Payments, Banking or Financial Services.
• Strong analytical, problem‑solving and troubleshooting skills.

Required skills

• Java (11+), Spring Framework 5, Spring Boot, Spring Cloud (Netflix OSS).
• OAuth2 authentication/authorization.
• JPA, ORM modeling and persistence frameworks.
• Design and development of RESTful APIs.
• Event‑Driven Architecture and asynchronous messaging.
• Git version control and collaborative workflows.
• English (advanced) and Spanish (mandatory) for technical communication.

What we offer

• Competitive salary package.
• Career growth and development opportunities in a global fintech.
• Access to challenging projects and continuous learning.
• Inclusive, collaborative and international work environment.
• Paid birthday leave.