What are the responsibilities and job description for the Java /Kotlin Developer position at ApTask?
Job Overview
We are looking for a Senior Java/Kotlin Engineer to help modernize a large-scale equity trading and finance platform. This role involves rebuilding core trading and post-trade systems using modern, event-driven and cloud-native technologies while maintaining the stability of existing production systems.
The ideal candidate will have strong Java expertise, hands-on experience with Kotlin, a solid understanding of capital markets, and experience building reliable, high-performance systems. You will work closely with engineering teams and business stakeholders, contribute to technical design decisions, and take ownership of development, testing, and production quality.
Key Responsibilities
- Modernize legacy trading and post-trade systems using Java, Kotlin, and event-driven architectures.
- Design reliable systems with proper error handling, event ordering, replay capabilities, and data integrity.
- Develop and maintain high-performance applications in a complex production environment.
- Follow Test-Driven Development (TDD) and take ownership of code quality and automated testing.
- Support CI/CD, trunk-based development, and frequent production releases with minimal or zero downtime.
- Collaborate with business stakeholders and technical teams to understand trading workflows and system requirements.
- Analyze, refactor, and improve legacy applications while maintaining system stability.
- Use AI-assisted development tools to support code analysis, testing, refactoring, and prototyping.
Required Qualifications
- 7 years of software engineering experience, with expert-level Java skills and practical Kotlin experience or the ability to work effectively with Kotlin.
- Strong knowledge of multithreading, performance optimization, and enterprise application development.
- Hands-on experience designing event-driven systems using messaging and event-sourcing patterns.
- Practical experience in capital markets, particularly trading or post-trade systems.
- Understanding of trade booking, position management, settlement, cash flow calculations, client reporting, or related financial operations.
- Strong experience with TDD, automated testing, CI/CD, trunk-based development, and iterative delivery.
- Proven ability to modernize large legacy systems without disrupting production operations.
- Ability to work independently, contribute to architecture discussions, and make sound technical decisions.
- Bachelor’s degree in Computer Science or a related field.
Preferred Qualifications
- Knowledge of Prime Brokerage, Cash Equities, or Synthetic Equity Swaps.
- Familiarity with corporate actions, regulatory reporting, and risk or valuation systems.
- Strong SQL Server skills, including T-SQL, database design, performance tuning, and complex data models.
- Experience with Kafka or similar event-streaming platforms and MongoDB.
- Familiarity with Kubernetes, OpenShift, cloud-native technologies, and monitoring tools such as OpenTelemetry, ELK, and Grafana.
- Experience using AI-assisted or agentic coding tools for legacy code analysis, refactoring, and test generation.