Senior Software Development Engineer

Clearwater Analytics; Greater London; On-site; GBP 70,000 - 110,000; Full time

Job summary

Clearwater Analytics is seeking a skilled Software Engineer to design, implement, and maintain high-quality code for complex financial software. You will work across cross-functional teams, applying strong mathematical foundations to build and optimise numerical routines in Python, C++, or Rust.

The role emphasizes scalable, well-tested code and collaboration with a broader platform. We welcome engineers from mid to senior levels, offering growth, mentorship, and opportunities to influence

Qualifications

• Proficiency in Python with performance-critical code.
• Experience with C++ or Rust for numerical routines.
• Strong mathematics background relevant to financial software.
• 2–10+ years of software development experience.

Responsibilities

• Design, build, deploy and maintain high-quality, well-tested code.
• Mentor less-experienced team members where appropriate.
• Use AI agents to speed up development safely and effectively.
• Develop mathematical models for pricing, risk metrics, and portfolio analytics.
• Ensure integration with distributed systems and service-oriented architectures.
• Troubleshoot production incidents promptly.

Skills

Python

C++

Rust

Mathematics

OOP

Education

Degree in Computer Science or Mathematics

Job description

We are seeking a skilled and motivated Software Engineer to join our dynamic team at CWAN. In this role, you will be responsible for designing, building, deploying, and maintaining high-quality code while collaborating with cross-functional teams to enhance our software offerings. This position is ideal for an engineer who is driven by client satisfaction and has a strong commitment to continuous learning and improvement. We use AI agents to speed up development safely and at the same time help clients achieve the same. A strong mathematical foundation is essential, as the role involves designing and optimising complex algorithms, numerical computations, and performance-critical financial systems. This is a software developer role that involves efficiently implementing mathematical calculations while at the same time integrating with the wider system.

We welcome applicants across a range of experience levels, from mid-level engineers building their expertise to seasoned seniors with deep domain knowledge. The scope of responsibilities and degree of autonomy will be tailored accordingly, offering room to grow for those earlier in their career and opportunities to lead and influence for those with more experience.

Responsibilities

Responsibilities will be scoped to match your level of experience. More experienced engineers will be expected to take on broader ownership, mentorship, and technical leadership.

Design, build, deploy, and maintain quality code that is simple, well-structured, clear, and well-tested.

Use AI agents to speed up development and advise others how to use them safely, both clients and internally.

Break down and solve complex problems efficiently, utilising research and collaboration as needed.

Implement and maintain multiple levels of automated testing (e.g., unit, integration, contract, end-to-end).

Mentor new and less-experienced team members, sharing knowledge and best practices. (More senior candidates)

Communicate effectively with stakeholders at all levels, including translating technical and mathematical concepts for non-technical audiences.

Coordinate with cross-functional teams to ensure successful integration of software applications.

Troubleshoot and resolve production incidents promptly and effectively.

Design and implement mathematical models and algorithms for financial calculations, including pricing, risk metrics, and portfolio analytics.

Perform numerical analysis and optimisation of computationally intensive routines, ensuring accuracy, correctness, and performance at scale while integrating seamlessly with the broader platform infrastructure.

Design and maintain integration layers between mathematical computation engines and broader system services, ensuring reliability, observability, and maintainability.

Required Skills

Proficiency in Python, including experience writing performance-critical code. Familiarity with C++ or Rust for low-level numerical routines is a strong plus.

Experience in the financial domain is a plus, although not required.

Strong command of a typed, object-oriented programming language, with an appreciation for system design, API boundaries, and clean integration patterns.

Deep knowledge of software methodologies, tools, and common architectural patterns.

Solid understanding of mathematics relevant to financial software, including linear algebra, calculus, probability, and statistics.

Experience implementing mathematical optimisations such as numerical solvers, interpolation methods, or matrix decompositions.

Ability to translate mathematical and financial specifications into efficient, well-tested code that integrates cleanly with distributed systems and service-oriented architectures.

Excellent teamwork and collaboration skills.

Ability to manage time effectively and deliver results within deadlines.

Commitment to continuous learning and professional development.

Exceptional analytical and problem-solving skills.

Education and Experience

Degree in Computer Science, Mathematics, or a related field.

2–10+ years of software development experience using Python or any other OOP language. We encourage candidates at allto apply — the role and level of responsibility will be shaped to fit your experience.

Demonstrated experience applying mathematical or quantitative methods in software projects is a plus.

Clearwater Analytics is a leading provider of web-based investment portfolio accounting and reporting services, managing over $6.4 trillion in assets for institutional investors worldwide.

Software Development Technology, Information and Internet Technology, Information and Media

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