Software Developer - Finance Technology in London

As a Senior Developer specialising in C# .NET, you will be a pivotal member of our Software Development team, driving an AI‑first approach to the creation and enhancement of secure, responsive web‑based finance platforms. These platforms will modernise and extend core PeopleSoft finance capabilities, delivering improved usability, performance, and scalability through contemporary web technologies. You will leverage modern AI‑assisted development tools and practices to accelerate delivery, improve code quality, and enhance developer productivity, while ensuring solutions meet the high standards of control, auditability, and reliability required within financial systems, including compliance with SOX (Sarbanes‑Oxley) requirements.

Your expertise in C# .NET, combined with your ability to apply AI‑driven techniques across the software development lifecycle, will be instrumental in delivering robust, scalable, and well‑governed applications. You will maintain a strong emphasis on testing, traceability, and deterministic system behaviour, ensuring that AI adoption enhances—rather than compromises—system integrity, auditability, and regulatory compliance.

In this role, you will apply your architectural experience to help mature our existing software estate, introducing intelligent automation where appropriate and transforming legacy PeopleSoft‑based functionality into cloud‑native, web‑first solutions. You will work closely with the platform engineering team to ensure seamless integration and deployment, while embedding AI‑enabled tooling and practices in a controlled, transparent, and compliant manner across the development lifecycle.

• Design, develop, and test components of modern, secure web‑based finance applications, applying AI‑assisted development practices to improve quality and delivery speed.
• Contribute to the overall architecture and design of technology solutions, incorporating AI‑enabled tooling and automation while ensuring control, transparency, and auditability.
• Develop solutions to a high standard that are maintainable, testable, and aligned to acceptance criteria, with a strong emphasis on traceability and deterministic behaviour in regulated environments.
• Adhere to development best practices and processes, including those required for SOX compliance (e.g. change control, segregation of duties, and auditability).
• Leverage AI tools responsibly across the software development lifecycle (e.g. code generation, testing, documentation), ensuring outputs are reviewed, validated, and compliant with engineering standards.
• Communicate effectively with team members, contribute ideas, and stay current with emerging technologies, particularly in AI and modern engineering practices.
• Liaise with business users to gather and refine application requirements, particularly in the context of modernising legacy finance platforms (e.g. PeopleSoft).
• Ensure delivered systems are production‑ready, secure, and well‑documented, supporting operational handover and ongoing audit requirements.
• Follow coding standards and defined development processes, ensuring consistency, quality, and compliance across all deliverables.
• Resolve third‑line support issues in a professional and timely manner, applying a structured and analytical approach to problem solving.

• Experience leveraging AI‑assisted development tools (e.g. code generation, automated testing, developer productivity tooling) to improve delivery speed and quality.
• Strong understanding of applying AI responsibly within the software development lifecycle, ensuring traceability, auditability, and control.
• Experience with NoSQL or RDMS databases.
• Experience with Infrastructure as Code, Terraform or equivalent.
• Modern CI/CD and DevOps practices.
• Cloud technology, ideally AWS (Amazon Web Services).
• Knowledge of BDD/TDD.
• Agile and scrum development methodologies.
• Methodical approach to software architecture and design and experience employing the right design choices for a given project.
• Understanding of controls required in regulated environments, including SOX (Sarbanes‑Oxley), with a focus on auditability, segregation of duties, and change control.
• Excellent verbal and written communication skills.
• A collaborative team player, approachable, self‑efficient, and able to foster a positive engineering culture, including adoption of AI‑first practices.
• Demonstrates curiosity, particularly in emerging technologies, AI capabilities, and continuous improvement of development practices.
• Resilient in a challenging, fast‑paced, and regulated environment.
• Excels at building relationships, networking, and influencing others across both technical and business teams.
• Strategic collaborator with insight and agility, able to anticipate future challenges, including those related to scale, regulation, and technology evolution, ensuring operational effectiveness.
• Dynamic work ethic: ability to adapt to changing electronic trading environment, proactively learning new technologies and adapting to new technologies, platforms, or requirements.
• Proactive and willing to pick up issues.

Marex is fully committed to the elimination of unlawful or unfair discrimination and values the differences that a diverse workforce brings to the company.