Senior C++ Programmer

A leading Cambridge technology company is seeking a Senior C++ Engineer to take ownership of a large, business-critical monolithic C++ codebase . This is a rare opportunity to shape the future of a mature system used globally, driving a long-term modernisation programme while embedding world-class engineering and testing practices.If you enjoy deep technical challenges, architectural thinking, and the satisfaction of turning a complex legacy system into a clean, modern, testable platform, this role will suit you perfectly.The RoleYou will become the technical lead responsible for the evolution of a substantial C++ codebase. Your mission spans architecture, refactoring, and quality engineering:Modernise a tightly coupled monolith into a more modular, maintainable architectureIntroduce modern C++ standards (C++17/20) , patterns, and toolingLead a structured programme of incremental refactoring and technical debt reductionEstablish and champion effective testing strategies across the codebaseImprove testability , reliability, and long-term maintainabilityDrive adoption of CI/CD, automated testing, and static/dynamic analysis toolsMentor engineers, lead design reviews, and set engineering standardsBalance strategic improvements with ongoing feature delivery and maintenanceThis is a hands-on leadership role: youll write code, shape architecture, and define how quality is engineered into the product.What Youll BringStrong expertise in modern C++ and experience working with large, legacy systemsA deep understanding of refactoring, modularisation, and architectural improvementProven experience designing and implementing robust testing frameworksAbility to improve test coverage , introduce automated tests, and enhance CI pipelinesExperience with unit testing, integration testing, and test-driven approachesA pragmatic mindset: improving quality without disrupting deliveryStrong communication skills and the ability to lead and mentor a teamNice to have:Experience with multithreading, performance optimisation, or low-level systemsFamiliarity with Linux development environmentsExposure to static analysis, sanitizers, fuzzing, or property-based testingWhy JoinHigh autonomy and ownership of a mission-critical codebaseA long-term modernisation roadmap you will shape from day oneA culture that values engineering excellence, testing discipline, and clean designCompetitive salary, hybrid working, and a Cambridge innovation environmentTPBN1_UKTJ