Senior Kotlin/Java Developer (Fintech) - remote friendly (EMEA)

Senior Kotlin/Java Developer (Fintech) - remote friendly (EMEA) SmartCore is a fintech holding building infrastructure for the next generation of payments. Our solutions cover the entire financial operations cycle - from core banking and processing to cards, wallets, and anti-fraud systems. We are a leading fintech company developing innovative solutions in payment processing and anti-fraud technologies. We create high-tech products that are reshaping the financial landscape and are looking for true professionals ready to tackle complex and ambitious challenges. About the Project You'll join a key team responsible for developing and evolving our core acquiring platform - a complex, high-load, microservices-based system operating 24/7. We handle the entire payment lifecycle, from initiation to clearing, ensuring minimal latency, high fault tolerance, and full compliance with strict security standards (PCI DSS). What You'll Do * Design and develop new microservices and business logic using Kotlin and Java. * Optimize the performance of existing system components and handle high-load areas of the codebase. * Make key architectural decisions aimed at improving fault tolerance, scalability, and platform security. * Integrate with third-party payment systems, banks, and processing centers. * Work with asynchronous data streams using Kafka and RabbitMQ. * Conduct code reviews, mentor less experienced colleagues, and promote best development practices. * Actively participate in R&D - exploring and integrating new technologies into the project stack. * Write unit and integration tests to maintain a high-quality codebase. Our Ideal Candidate * Has at least 10 years of commercial backend development experience with Java/Kotlin. * Demonstrates expert-level proficiency in Kotlin: understands idioms, coroutines, functional features, and applies them effectively. * Possesses deep knowledge of Java Core and the JVM ecosystem. * Has excellent command of Spring Boot - not only building REST APIs but also understanding its internals, auto-configuration, Spring Security, and Actuator. * Expert in PostgreSQL - experienced in designing complex data schemas, optimizing queries, understanding transaction isolation levels, and replication mechanisms. * Experience with MongoDB. * Hands-on experience building systems with Kafka - understanding broker mechanics, producer/consumer patterns, and message delivery guarantees. * Familiar with RabbitMQ and Redis (including caching, pub/sub, and distributed locks). * Experience designing and building distributed, fault-tolerant systems (microservices architecture, CQRS, Event Sourcing). * Comfortable with modern AI technologies, including AI agents, and capable of applying various LLMs in practice. * Understanding of networking protocols (TCP/IP, HTTP/2, gRPC). * Experience with containerization and orchestration tools (Docker, Kubernetes). * Writes clean, maintainable, and well-tested code. * Highly

autonomous, proactive, and takes full ownership of product quality and outcomes. * Fluent in Russian (B2 or higher) - required for daily communication within the team. Nice to Have * Experience in fintech or payment processing; familiarity with PCI DSS. * Experience with reactive stacks (Project Reactor, WebFlux). * Familiarity with monitoring and tracing tools (Prometheus, Grafana, Jaeger). * Experience with load testing tools (JMeter, Gatling). We Offer * A competitive salary, discussed individually with each candidate. * A modern technology stack and minimal bureaucracy. * Budget for training, professional conferences, and books. * Corporate access to all top-tier LLMs with maximum configurations. * A team of passionate experts where your voice will always be heard. How to Apply Feel free to apply directly via LinkedIn or by sending your CV to stanislav.pavlov[@]smartcore.pro - if you're ready for serious architectural challenges and want to build a product you can be proud of! Seniority level Mid-Senior level Employment type Full-time Job function Engineering and Information Technology #J-18808-Ljbffr