Senior Java/Kotlin Engineer (Hybrid in Jersey City, NJ)
About the role
We are looking for a Senior Java/Kotlin Engineer to work with our client - Tier 1 investment bank on its Equity Accelerator program, a multi-year strategic initiative to modernize the Prime Finance Equities platform. The program is re-engineering core trading systems, building new data and market-expansion platforms, and launching advanced client features such as cross-margining and credit financing, replacing legacy architecture with event-driven, cloud-native systems designed for institutional-grade stability, throughput and extensibility. This is not a greenfield build. You will work directly within a complex, financially significant production system, critically assessing system behavior 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.
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.
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.
Requirements
- Expert-level Java, with Kotlin experience or a clear appetite for it (enterprise-grade systems, multi-threading, performance).
- P