Senior Kotlin Developer

We are looking for a Senior / Lead Kotlin Engineer to join a critical initiative re-engineering core trading and post-trade platforms. You will focus on modernizing large-scale legacy components into high-performance, event-driven, cloud-native services using Java and Kotlin, all while maintaining absolute stability on a live, financially significant platform. Responsibilities Re-engineer core trading and post-trade systems into event-driven, cloud-native services on the JVM (Java and Kotlin).Modernize legacy components while maintaining the stability of a live, financially significant platform.Build new data and market-expansion platforms that underpin the programme, alongside plumbing for cross-margining and credit financing.Design for the realities of event-driven systems: failure handling, ordering guarantees, replay semantics, and data integrity under market pressure.Practice TDD and shift-left testing as default, utilizing local containerized dependencies and owning quality end-to-end.Deliver iteratively using trunk-based development, CI/CD, and frequent zero-downtime production releases.Engage directly with business stakeholders and upstream/downstream teams to build domain knowledge without relying on Business Analysts.Leverage AI-assisted and agentic development tools as a genuine accelerator for legacy code analysis, test generation, prototyping, and refactoring. Requirements Expert JVM Engineering: Expert-level Java expertise with production Kotlin experience (or a clear appetite to adopt it) for multi-threaded, high-performance enterprise systems.Event-Driven Systems: Practical experience designing message-passing and event-sourcing architectures, including failure handling, ordering guarantees, and replay semantics.Strict TDD Discipline: TDD as a core engineering practice; ability to design for testability and demonstrate end-to-end quality ownership.Capital Markets & Post-Trade Domain: Proven hands-on experience in trading or post-trade environments (trade lifecycle, booking, position management, cashflow calculation, settlement, wires, client reporting, and accounting principles).Iterative & Continuous Delivery: Proven track record with short feedback loops, trunk-based development, CI/CD, and regular zero-downtime production releases.Legacy System Refactoring: Proven ability to analyze, refactor, and modernize large-scale legacy systems while maintaining operational stability.Senior Autonomy: Strong technical communication skills to contribute to design discussions, push back constructively on technical decisions, and operate with minimal supervision in complex production environments. Nice to have Domain Specialties: Deep understanding of Prime Brokerage, Synthetic (Swaps), or Cash Equity operational flows.Regulatory & Risk Integration: Familiarity with corporate actions, regulatory reporting obligations (e.g., 871(m), EMIR, MiFID), and integrating with risk/valuation systems in an equities context.Database Depth: Strong SQL Server depth (T-SQL, schema design, performance tuning) in high-transaction environments, alongside experience with Kafka and MongoDB at scale.Cloud-Native & Observability: Experience deploying on Kubernetes/OpenShift with observability using OpenTelemetry, ELK, and Grafana.AI-First Workflows: Hands-on experience with agentic coding workflows for legacy code analysis, automated test generation, and refactoring. We offer Opportunity to work on bleeding-edge projectsWork with a highly motivated and dedicated teamCompetitive salaryFlexible scheduleBenefits package - medical insurance, sportsCorporate social eventsProfessional development opportunitiesWell-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.