Backend Software Engineer - Core Business Systems (CBS)
STS Digital (www.stsdigital.io) is a leading regulated digital asset trading firm specialising in OTC trading and market making. While trading is headquartered in Bermuda, technology development is provided by a global engineering team.
We are seeking a Backend Software Engineer to join the Core Business Systems (CBS) team. This role focuses on building and maintaining the systems that support the operational backbone of the business, including accounting, reporting, treasury automation, and trade lifecycle management. The engineer will work closely with the CBS Team Lead and other engineering teams to deliver reliable, auditable, and scalable backend services.
Primary Responsibilities:
* Design, implement, test, deploy, and maintain backend services supporting core business operations.
* Develop and enhance systems covering: Accounting and trade reporting; Trade and options lifecycle management; Treasury automation and transfer management.
* Admin and operational tooling (users, accounts, entity mapping)
* Design and maintain relational database schemas, with a strong focus on correctness, performance, and auditability.
* Build and maintain internal APIs used by OTC, Markets, Integrations, and operational teams.
* Work closely with stakeholders to ensure systems meet operational, regulatory, and reporting requirements.
* Investigate and resolve production issues, ensuring data integrity and minimal business impact.
* Participate in code reviews, testing, and continuous improvement of system quality and performance.
* Collaborate with the Principal Engineer and other teams to align on standards, architecture, and best practices.
Expected Qualifications:
Essential
* 3+ years’ experience in backend software engineering.
* Strong hands-on experience with C# (or another strongly typed language).
* Solid experience with relational databases, ideally PostgreSQL.
* Experience designing data models and working with complex business domains.
* Strong problem-solving skills and a structured approach to debugging and troubleshooting.
* Comfortable working on business-critical, data-sensitive systems.
* Good verbal and written communication skills.
* Fluent in English, both written and spoken.
Desirable
* Experience in financial services, trading, accounting, or operational systems.
* Exposure to trade lifecycle, treasury, or reconciliation workflows.
* Experience with Python and/or React.
* Familiarity with cloud-based systems (AWS).
* Experience building or consuming internal APIs.
* Understanding of audit, reporting, or regulatory requirements in technology systems.
Our Tech Stack
* Backend: C#, Python
* Frontend: React
* Databases: PostgreSQL, DynamoDB
* Infrastructure: AWS (EKS, EC2)
* Version Control & CI/CD: GitHub
More Info
The CBS team is responsible for systems that underpin the firm’s operational integrity and regulatory posture. This role is suited to an engineer who enjoys working with complex data, business rules, and operational workflows, and who values correctness, reliability, and long-term system quality.