Company description We’re looking for a Senior Java Engineer to join a large-scale financial services platform in the middle of an active Java modernization journey. In this role, you’ll help migrate and evolve legacy systems toward modern Java (17/21) and cloud-native architectures on AWS, working on performance-critical, secure, and highly scalable services that run in production at scale. Overview Your Impact Join a large-scale financial services platform, supporting business-critical systems with high standards of reliability, security, and performance. Play a key role in the ongoing modernization of enterprise Java applications, including: Migrating legacy Java services to modern Java versions (Java 17 / Java 21) Refactoring existing codebases to improve scalability, performance, and maintainability Contributing to architectural evolution toward modern, cloud-native patterns Design and enhance high-performance backend systems, supporting both new features and platform evolution. Collaborate directly with senior client stakeholders in a highly autonomous, client-facing environment. Contribute to platform stability by participating in production-related activities, while keeping development and modernization as the primary focus. Qualifications Your Skills and Experience Strong hands-on experience with Java in enterprise-scale systems, ideally within regulated or high-availability environments. Proven experience working with modern Java versions, including Java 17 and Java 21. Solid understanding of Core Java fundamentals, including: Java Collections Framework (List, Set, Map, concurrency-aware collections) Object-oriented principles and enterprise design patterns Strong background in concurrency and multithreading, including: ExecutorService, thread pools, synchronization strategies Designing thread-safe, high-performance systems Experience optimizing backend performance across: REST APIs SQL queries and data access layers Microservices interactions and data processing flows Strong understanding of REST API concepts, including: HTTP methods, status codes, idempotency API versioning, error handling, and performance considerations Hands-on experience implementing security best practices, including: Authentication and authorization with Spring Security OAuth and JWT Proven experience in JVM analysis and tuning, including: Memory management and garbage collection Thread dumps vs. heap dumps: when to use each and how to analyze them Performance troubleshooting using tools such as JConsole, JVisualVM, or similar Understanding and practical use of JMX Strong debugging skills, including: Local debugging and remote debugging of Java applications Structured debugging methodologies for production and non-production environments Familiarity with basic Unix/Linux commands for troubleshooting and system inspection. Solid understanding of build and dependency management, including: Maven concepts (lifecycle, dependencies, plugins, profiles) Familiarity with NoSQL databases, with MongoDB preferred. Understanding of event-driven architectures, including Kafka or similar messaging platforms. Experience working in AWS-based environments (strong plus), with exposure to multi-cloud or hybrid cloud environments as a bonus. Strong communication skills, able to explain technical decisions and findings clearly in discussions with senior stakeholders. Set Yourself Apart With Experience modernizing enterprise Java platforms in financial or regulated industries. Demonstrated JVM tuning and performance optimization work. Background designing high-throughput, secure, event-driven backend systems. Exposure to cloud-native, multi-cloud, or hybrid architectures. Comfort leveraging AI tools to improve engineering productivity. Experience working directly with senior stakeholders in client-facing roles.