Mid-Senior Java Software Engineer (Remote - Argentina) - ARG112-DV

OKTO’s continuous growth demands high-caliber candidates who embody professionalism, passion, and creativity. For those who join us, we offer significant career advancement, stimulating challenges, and a clear runway for growth. OKTO is the next-generation Payment Service Provider — AI-native, precision-engineered, and relentlessly merchant-obsessed. Built for merchants operating in the most complex and demanding eCommerce sectors, our platform goes far beyond transaction processing. We solve for scale, compliance, and performance with one unshakable focus: delivering outcomes that power merchant growth. From payments and banking to treasury and settlement, we engineer the financial infrastructure that gives our partners a competitive edge. The result? Faster onboarding, smarter operations, and resilient, real-time performance. At OKTO, we enable merchants to Play Differently, transforming payments from routine transactions into true differentiators that deliver personalized, frictionless experiences. Our AI-native innovation harnesses data and insight to power every decision, while our proprietary in-house engineering ensures precision and control. Combined with deep, trust-based relationships worldwide, we’re redefining what it means to build, scale, and win in complex digital commerce. Summary As a Java Middleware Engineer, you will play a key role in designing, developing, and maintaining the middleware services that power our next-generation payment platform. You will contribute to the development of scalable, secure, and high-performance applications that process millions of financial transactions, while collaborating with Product, Architecture, Infrastructure, QA, and Security teams. Key Responsibilities - Design, develop, and maintain middleware applications and backend services using Java and Spring technologies. - Develop new product features and platform capabilities based on business and technical requirements. - Build scalable, resilient, and high-performance microservices that support payment processing and financial transaction workflows. - Write clean, maintainable, and performance-optimized code, ensuring high-quality standards and comprehensive unit test coverage. - Participate in the design and implementation of distributed systems and event-driven architectures. - Develop and maintain RESTful APIs and secure service integrations using modern authentication mechanisms such as OAuth2. - Support System Integration Testing (SIT), User Acceptance Testing (UAT), and Production environments, identifying and resolving issues to ensure platform stability. - Collaborate with cross-functional teams, including Product Managers, QA Engineers, DevOps Engineers, and Solution Architects, to deliver high-quality software solutions. - Participate in Agile ceremonies, code reviews, technical discussions, and knowledge-sharing initiatives. - Contribute to continuous improvement by identifying opportunities to optimize software quality, development processes, and system performance. - Work with version control systems and CI/CD pipelines, following engineering best practices and software development standards. - Produce technical documentation, including product specifications, design documentation, and implementation details. Requirements - Bachelor's degree in Computer Science, Computer Engineering, Software Engineering, Information Technology, or a related field. - Minimum of 5 years of professional experience developing middleware or backend applications using Java. - At least 1 year of hands-on experience with Java 11 or newer. - Proven experience working within the FinTech, Payments, Banking, or Financial Services industry. - Strong understanding of Object-Oriented Design (OOD), SOLID principles, and Functional Programming concepts. - Experience designing and developing microservices architectures using Spring Boot and Spring Cloud (Netflix OSS). - Solid knowledge of the Spring Framework 5 ecosystem. - Experience implementing secure authentication and authorization using OAuth2. - Experience with JPA, ORM modeling, and persistence frameworks. - Strong experience designing and developing RESTful APIs. - Familiarity with Event-Driven Architecture, asynchronous messaging, and distributed software design patterns. - Experience working with Git and collaborative source control workflows. - Good understanding of software development best practices, including unit testing, clean code principles, and code review processes. - Strong analytical, problem-solving, and troubleshooting skills. - Ability to work independently while collaborating effectively within an international engineering team. - Excellent technical writing skills for documenting requirements, software designs, and technical specifications. Preferred Qualifications - Experience with cloud platforms such as AWS. - Familiarity with CI/CD pipelines and DevOps practices. - Experience working in high-volume transaction processing environments. - Knowledge of payment processing concepts, transaction lifecycle, settlement, reconciliation, or payment gateway integrations. - Experience with monitoring, logging, and application performance optimization. Languages - Advanced English (mandatory), with the ability to participate in technical discussions, collaborate with international teams, and produce technical documentation. - Spanish (mandatory). Please submit your resumé in English. Benefits - Competitive Compensation - Competitive salary package. - Career Growth - Career development opportunities in a growing global fintech. - Continuous Learning - Access to challenging projects and continuous learning opportunities. - Inclusive Environment - Collaborative, diverse, and international work environment. - Birthday Leave - Paid day off on your birthday. Originally posted on Himalayas