Senior Java Software Engineer

Grid Dynamics is looking for and engineer who will work directly within a complex, financially significant production system, critically assessing system behaviour and data integrity in dynamic market environments, contributing to architectural decisions, and operating with a high degree of autonomy within an experienced engineering group. This is not general-purpose Java delivery: the domain complexity and the engineering standards applied by the internal team demand engineers with real depth. Requirements: Expert-level Java, with Kotlin experience or a clear appetite for it (enterprise-grade systems, multi-threading, performance). Practical experience designing and building event-driven systems on message-passing and event-sourcing patterns, including failure handling, ordering guarantees and replay semantics. Test-Driven Development as a practice, not an aspiration: you own quality end-to-end, you design for testability, and you can demonstrate it through how you approach a problem (this is assessed at interview). Hands-on experience in or alongside a capital markets trading or post-trade environment: the trade lifecycle, trade booking and position management, and post-trade operations such as cashflow calculation, settlement and wires, client reporting, and accounting principles. You should be able to back this up with concrete examples, not high-level familiarity. A track record in genuine iterative delivery incl. short feedback loops, trunk-based development, CI/CD, and regular zero-downtime production releases. No waterfall projects labelled as agile. Proven ability to analyse, refactor and modernise large-scale legacy systems while maintaining stability. Senior-level autonomy: you contribute to design discussions, push back constructively on technical decisions, and operate with minimal supervision in a complex production environment. Responsibilities: Re-engineering core trading and post-trade systems into event-driven, cloud-native services on the JVM (Java and Kotlin). Modernising legacy components while keeping a live, financially significant platform stable. Building the new data and market-expansion platforms that underpin the programme, and the plumbing for advanced client features such as cross-margining and credit financing. Designing for the realities of event-driven systems: failure handling, ordering guarantees, replay semantics, and data integrity under market pressure. Practising TDD and shift-left testing as the default. Local-first testing with containerised dependencies, fast feedback loops, and owning the quality of your deliverables end-to-end rather than handing it to a QA group. Delivering iteratively: trunk-based development, CI/CD, and frequent (weekly or better) production releases during business hours with no service interruption. Engaging directly with business stakeholders and upstream/downstream teams to build your own domain knowledge, rather than relying on Business Analysts to hold it for you. Using AI-assisted and agentic development tooling as a genuine accelerator for analysis of legacy code, test generation, prototyping and refactoring. We offer: Opportunity to work on cutting-edge projects Work with a highly motivated and dedicated team Competitive salary Flexible schedule Benefits package - medical insurance, vision, dental, etc. Corporate social events Professional development opportunities Well-equipped office About us: Grid Dynamics (NASDAQ: GDYN) is a leading provider of technology consulting, platform and product engineering, AI, and advanced analytics services. Fusing technical vision with business acumen, we solve the most pressing technical challenges and enable positive business outcomes for enterprise companies undergoing business transformation. A key differentiator for Grid Dynamics is our 8 years of experience and leadership in enterprise AI, supported by profound expertise and ongoing investment in data, analytics, cloud & DevOps, application modernization and customer experience. Founded in 2006, Grid Dynamics is headquartered in Silicon Valley with offices across the Americas, Europe, and India. Grid Dynamics