Software Engineer II in Belfast

Apex Fintech Solutions (Apex) powers innovation and the future of digital wealth management by building tech-forward solutions that help simplify, automate, and facilitate access to financial markets for all. Our robust suite of fintech software enables us to support clients such as Stash, Betterment, SoFi, Webull, and eToro, amongst many others; collectively, Apex powers access to the stock market for over 22+ million end customers.

At Apex, we are changing how the securities industry operates by reinventing the status quo, which was manual, slow, and accessible only by the ultra-wealthy. We’re digitizing and democratizing systems so that everyone has an opportunity to invest. When you’re at Apex, you drive this change. You’re part of a global team with a clear vision: to be the trusted technology that powers the digital economy. Our offices in Austin, Dallas, Chicago, New York, Portland, Belfast, and Manila are home to over 1,000 employees. Together, we’re shaping the future of financial innovation. Embrace change. Solve big. Win together. And be G.R.E.A.T. — grit, results, empathy, accountability, and teamwork — with Apex.

We’re proud to be recognized for the innovative work we do, the purpose-driven nature of our work, and the collaborative culture we’ve created. Here are just a few of the many awards we’ve recently received:

• Best Places to Work — 2026, 2025, 2024, 2023 (Presented by BuiltIn)
• WealthTech of the Year — 2025 (Presented by US FinTech Awards)
• The World’s Top 250 Fintech Companies — 2024 (Presented by CNBC)

As a Software Engineer II, you will play a pivotal role in designing, building, and optimizing solutions that power this transformation. You’ll have the opportunity to work on cutting-edge software architectures, solve challenging problems, and collaborate with diverse teams to create impactful solutions for our fast-paced fintech environment. We’re looking for engineers who thrive when tackling complex, meaningful challenges and have a strong foundational knowledge of software development across multiple languages and frameworks. We are innovators who operate in a collaborative, entrepreneurial environment while valuing continual learning, flexibility, and adaptability. If you’re looking for a role that combines creative problem-solving with the drive to make an immediate impact on an evolving industry, let’s change everything together.

Working on the Billing Engineering team, this role will involve:

• Building the services for our new GCP-based Billing system for clients on the Apex Ascend platform
• Maintaining our current Billing application for existing customers

Duties / Responsibilities:

• Implement features and enhancements across billing microservices, writing well-tested Java code for charge calculations, rate configurations, settlement processing, and integrations with internal and external systems
• Participate in the full development lifecycle, from understanding requirements and writing code to testing, code reviews, and deploying changes using Bazel build tools and established CI/CD workflows
• Write and maintain automated tests to ensure code quality and system reliability, including unit tests, integration tests, and working with testing frameworks to validate billing logic and data processing workflows
• Debug and fix bugs in production and non-production environments, using Datadog logs and metrics to investigate issues in billing services, database queries, and service-to-service communication
• Collaborate with team members on technical tasks, participating in code reviews, pair programming sessions, and team discussions to deliver features and improvements within the billing domain
• Work with databases and data systems, writing SQL queries, implementing database migrations with Flyway, and integrating with PostgreSQL, BigQuery, and other data storage systems used in billing operations
• Learn and apply best practices for microservices development, including gRPC/Protobuf APIs, event-driven architectures with PubSub, monitoring and observability, and financial systems integration patterns

Education And Experience:

• A Bachelor’s degree in Computer Science, Computer Engineering, or a related field (or equivalent professional experience) required
• 3+ years of professional development experience with a multi-person engineering team, leveraging modern practices like code reviews, CI/CD, and trunk-based development.
• Experience in cloud ecosystems, particularly Google Cloud Platform services like BigQuery, Pub/Sub, or Cloud Functions.

Required Skills / Abilities:

• Proficiency in software development using modern programming languages like Python, Java, Go, or similar tools.
• Strong understanding of microservices architecture and CI/CD pipelines.
• Proven expertise in relational databases and familiarity with distributed systems or data-intensive platforms including SQL query expertise.
• Familiarity with software development best practices like testing, version control, and agile processes.
• A problem-solving mindset, with the ability to think critically through challenging engineering scenarios.
• An innate passion for learning new technologies, frameworks, and tools to contribute to dynamic software solutions.

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.

We offer a robust package of employee perks and benefits, including a market-leading salary with an annual bonus, 28 days of annual leave plus 10 Northern Ireland national holidays, a training and development budget, and a pension matched up to 7%. Our benefits also cover private health insurance for medical, dental, and optical care, and life insurance. We emphasize work-life balance with flexible working hours, parental leave, a modern city center office, and a hybrid work schedule that allows for greater flexibility by partially working from home. Additional perks include monthly catered lunches, unlimited drinks and snacks, hackathon events, poker tournaments, and a charitable matching gift program.

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.

Apex Fintech Solutions is committed to creating an inclusive and accessible workplace for all candidates, including those with disabilities. We are dedicated to ensuring equal employment opportunities and providing reasonable accommodations to qualified individuals 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.