Senior Java/Kotlin Engineer – Equity Prime Finance

Grid Dynamics; Greater London; Hybrid; GBP 120,000 - 150,000; Full time

Benefits offered by this job

Bleeding-edge projects

Well-equipped office

Corporate events

Professional development

Flexible schedule

Competitive salary

Medical insurance

Sports

Job summary

Grid Dynamics in London is seeking a Senior Java/Kotlin Engineer to re-engineer Prime Finance trading and post-trade systems within a live production environment. You will design, develop and deploy resilient services in Java and Kotlin, collaborating with stakeholders to modernise legacy components and deliver complex financial workflows.

The role requires deep capital markets knowledge, strong multi-threading and event-driven architecture skills, and a commitment to trunk-based development,

Qualifications

• Expert Java development experience.
• Hands-on experience designing and developing event-driven systems.
• Experience within capital markets, trading or post-trade environments.

Responsibilities

• Re-engineer core trading and post-trade systems using Java and Kotlin.
• Design and develop event-driven, message-based and event-sourced systems.
• Design for failure handling, ordering guarantees and data integrity.
• Modernise and refactor large-scale legacy systems while maintaining production stability.
• Build data and market-expansion platforms supporting the Equity Accelerator programme.
• Apply TDD and shift-left testing throughout the development lifecycle.
• Deliver through trunk-based development and CI/CD.
• Support frequent, zero-downtime production releases.

Skills

Java expert

Kotlin experience

Concurrency & performance

Event-driven design

Event sourcing

TDD experience

Automated testing

Capital markets knowledge

Trading/post-trade

Legacy refactoring

CI/CD / trunk-based

Zero-downtime releases

Autonomous work

Strong communication

Job description

London | Hybrid | Tier 1 Investment Bank

The Opportunity

We are partnering with a Tier 1 investment bank on a major, multi-year Equity Accelerator programme focused on modernising its Prime Finance Equities platform. The programme is re-engineering core trading and post-trade systems, introducing new data and market-expansion platforms, and enabling advanced client capabilities including cross-margining and credit financing. You’ll be working within a live, financially significant production environment, replacing legacy architecture with modern event-driven, cloud-native systems designed for institutional-grade stability, throughput and extensibility. This is not a general-purpose Java development role. The team requires engineers with strong technical depth, genuine capital-markets experience and the ability to operate autonomously within a complex production environment.

Responsibilities

The Role

As a Senior Java/Kotlin Engineer, you’ll contribute to the re-engineering of core Prime Finance trading and post-trade systems across the JVM ecosystem. You’ll work closely with experienced engineers and business stakeholders, contributing to architectural decisions, modernising legacy components and building highly resilient services capable of handling complex financial workflows and market-driven events.

Key Responsibilities

• Re-engineer core trading and post-trade systems using Java and Kotlin
• Design and develop event-driven, message-based and event-sourced systems
• Design for failure handling, ordering guarantees, replay semantics and data integrity
• Modernise and refactor large-scale legacy systems while maintaining production stability
• Build data and market-expansion platforms supporting the wider Equity Accelerator programme
• Develop technology supporting advanced capabilities such as cross-margining and credit financing
• Apply TDD and shift-left testing throughout the development lifecycle
• Build local-first automated tests using containerised dependencies
• Deliver through trunk-based development and CI/CD
• Support frequent, zero-downtime production releases
• Work directly with business stakeholders and upstream/downstream teams to develop strong domain knowledge
• Analyse complex production behaviour and resolve technically challenging issues
• Use AI-assisted and agentic development tools to accelerate legacy analysis, refactoring, testing and prototyping
• Contribute to technical design discussions and challenge decisions constructively where appropriate

Requirements

Essential Experience

• Expert-level Java development experience
• Strong experience with Kotlin, or a clear appetite to develop in Kotlin
• Strong understanding of multi-threading, concurrency and performance
• Hands-on experience designing and developing event-driven systems
• Practical understanding of message passing, event sourcing, failure handling, ordering and replay
• Proven Test-Driven Development (TDD) experience
• Strong automated testing and design-for-testability practices
• Experience within capital markets, trading or post-trade environments
• Strong understanding of areas such as:
• Trade lifecycle
• Trade booking
• Position management
• Cashflow calculation
• Settlement and wires
• Client reporting
• Financial accounting principles
• Experience modernising and refactoring large-scale legacy systems
• Genuine experience working with iterative delivery, trunk-based development and CI/CD
• Experience delivering frequent, reliable zero-downtime production releases
• Ability to work autonomously within complex production environments
• Strong communication skills and the confidence to contribute to architectural and technical decisions

Technology Environment

Java | Kotlin | JVM | Event-Driven Architecture | Event Sourcing | Kafka | SQL Server | T-SQL | MongoDB | Kubernetes | OpenShift | Cloud | OpenTelemetry | ELK | Grafana | CI/CD | TDD | Git | Trunk-Based Development | Docker | AI-Assisted Development

The Opportunity

This is an opportunity to work on a strategic, multi-year transformation at the heart of a global Prime Finance business, rather than simply maintaining an existing application. You’ll gain deep exposure to Equity Prime Finance, trading and post-trade technology, work alongside highly experienced engineers and play a meaningful role in replacing legacy systems with modern, resilient and scalable architecture. If you’re a senior Java engineer who combines deep engineering ability with genuine capital-markets domain knowledge, this is an opportunity to work on technically challenging systems with significant business impact.

Nice to have

Highly Desirable

• Prime Brokerage experience
• Synthetic / Swap or Cash Equity operational flows
• Corporate Actions
• Regulatory reporting, including 871(m), EMIR or MiFID
• Integration with risk and valuation systems
• Strong SQL Server / T-SQL experience
• Database schema design and performance tuning
• Kafka or equivalent event-streaming platforms at scale
• MongoDB
• Kubernetes / OpenShift
• Cloud-native operational practices
• OpenTelemetry, ELK and Grafana
• AI-first development using agentic coding tools for legacy analysis, refactoring and test generation

We offer

• Opportunity to work on bleeding-edge projects
• Work with a highly motivated and dedicated team
• Competitive salary
• Flexible schedule
• Benefits package - medical insurance, sports
• 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.