Senior Software Engineer; Java

Apex Fintech Solutions, is a leading innovator in the fintech sector, leveraging advance...

Apex Fintech Solutions is seeking a
Senior Software Engineer
to play a key role on our Billing engineering team, responsible for designing, developing, and maintaining high-quality software solutions. You will leverage your experience and expertise to contribute to the software development lifecycle, from requirements analysis and implementation to testing and deployment. You will collaborate with team members and cross-functional partners to deliver scalable, reliable, and efficient software products that meet the needs of our users and business objectives.

• Build and maintain microservices within the billing platform, including calculation, rates, settlement, and charge services, writing production-quality Java code that handles complex financial workflows and data processing
• Own end-to-end delivery of features from design through deployment, implementing rate configurations, charge calculation logic, settlement generation, and integrations with external systems like Big Query and third‑party financial platforms
• Optimize performance‑critical code paths for high‑volume billing operations, utilizing Postgre
  
  SQL with jOOQ, implementing caching strategies, and ensuring efficient data processing for large‑scale financial calculations
• Write comprehensive tests and ensure code quality, maintaining high test coverage across unit, integration, and end‑to‑end tests using the Bazel build system and established testing frameworks
• Collaborate with team members on technical design and code reviews, contributing to API design with gRPC and Protobuf, database schema migrations with Flyway, and event‑driven architectures using Pub Sub
• Debug and resolve production issues, leveraging Datadog monitoring, logs, and metrics to investigate and fix issues in billing calculations, settlement processes, and service integrations
• Contribute to technical improvements and best practices within the team, sharing knowledge about billing domain logic, system architecture patterns, and development workflows with peers

• Bachelor's degree in Computer Science, Engineering, or related field (or equivalent work experience) required; advanced degree preferred
• 5+ years of experience in software development with a strong proficiency in one or more programming languages, including Java, Python
• Experience with automated testing frameworks and methodologies for backend services
• Experience contributing to topics and participating in technical direction and implementation strategy for projects
• Experience with CI/CD (Continuous Integration/Continuous Deployment) pipelines and tools, automating build, test, and deployment processes
• Experience with cloud platforms (e.g., AWS, Azure, GCP)
• Experience with SQL including the ability to write complex queries and optimise database performance, e.g. Postgres, MS SQL Server
• Experience in financial services a plus

• Ability to troubleshoot production systems, diagnose issues, and implement effective solutions to ensure system reliability and availability
• Strong problem‑solving abilities, analytical thinking, and attention to detail
• Effective communication and interpersonal skills, with the ability to collaborate effectively with cross‑functional teams and contribute to technical discussions
• Knowledge of Agile software development methodologies and tools (e.g., Scrum, Kanban, Jira)

Please note this job description is not designed to cover or contain a comprehensive listing of activities, duties, or responsibilities required of the employee for this job. Duties, responsibilities, and activities may change at any time with or without notice.