Senior Java Engineer

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.

* 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.

* 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.