Staff Software Engineer in Belfast

We’re seeking an innovative, passionate, and forward‑thinking individual to join us as a Staff Software Engineer. This is an opportunity to join a fast‑paced team with the urgency of a startup and the expertise of an established organisation. Your products will process billions of transactions per day in real‑time and power both startup and established industry participants.

DUTIES AND RESPONSIBILITIES

• Design and evolve microservices architecture for the billing platform, ensuring scalability, reliability, and maintainability across the distributed system.
• Lead technical decision‑making for complex billing workflows involving rate configurations, charge calculations, settlement generation, and end‑customer processing, balancing business requirements with system performance and cost constraints.
• Drive performance optimization of data‑intensive operations leveraging BigQuery, PostgreSQL, and caching strategies to handle high‑volume financial calculations and reporting at scale.
• Mentor and guide engineers across multiple teams, establishing best practices for Java development, Bazel build configurations, database migrations with Flyway, and event‑driven architectures.
• Own system reliability and operational excellence, implementing comprehensive monitoring with Datadog, designing robust error handling and validation, and ensuring SLOs are met for critical financial processes.
• Collaborate cross‑functionally with product, finance, and compliance teams to translate business requirements into technical solutions, managing integrations with external financial systems and internal platform services.
• Establish and maintain technical standards for the billing domain, including testing strategies, API design with gRPC and Protobuf, database schema evolution, and deployment practices across multiple environments.

EDUCATION AND EXPERIENCE

• Bachelor’s degree in Computer Science, Engineering, or related field (or equivalent work experience) required; advanced degree preferred.
• 8+ years of experience in software development with a deep knowledge in one or more programming languages, including Java and Python.
• Experience with automated testing frameworks and methodologies for backend services.
• Experience contributing to epics and participating in technical direction and implementation strategy for projects.
• Experience with CI/CD 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.

REQUIRED SKILLS AND ABILITIES

• Expertise with containerization (Docker), orchestration (Kubernetes), cloud platforms (GCP, AWS), and infrastructure automation (Terraform, Ansible).
• Expertise in software release tooling, GitOps, and CI/CD practices.
• Excellent communication skills and the ability to collaborate effectively with cross‑functional teams.
• Knowledge of API management methodologies, security practices, and traffic management strategies.

WORK ENVIRONMENT

This role operates in a hybrid office environment with two days per week in the office.

BENEFITS

• Market‑leading salary with annual bonus.
• 28 days of annual leave plus 10 Northern Ireland national holidays.
• Training and development budget.
• Pension matched up to 7%.
• Private health insurance for medical, dental, and optical care.
• Life insurance.
• Flexible working hours, parental leave, modern city‑center office, and hybrid work schedule.
• Monthly catered lunches, unlimited drinks and snacks, hackathon events, poker tournaments, charitable matching gift program.

EEO STATEMENT

Apex Fintech Solutions is an equal opportunity employer that does not discriminate on the basis of race, color, religion, sex (including pregnancy, sexual orientation, and gender identity), national origin, age, disability, veteran status, marital status, or any other protected characteristic. Our hiring practices ensure that all qualified applicants receive fair consideration without regard to these characteristics.

DISABILITY STATEMENT

Apex Fintech Solutions is committed to creating an inclusive and accessible workplace for all candidates, including those with disabilities. If you require reasonable accommodations to participate in the application or interview process, please submit your request via the Candidate Accommodation Requests Form. We will work with you to provide the necessary accommodations to ensure your full participation in our hiring process.