Lead Security Engineer – Proprietary Trading Firm – London (On-Site) – Up to £140,000 Base Salary + 20% Bonus A leading global trading and investment firm is seeking a Lead Security Engineer to play a pivotal role in building and shaping its security practice. This is a senior, hands-on role with genuine influence across network, cyber, and cloud security, combining deep technical expertise with strategic direction. This position is ideal for someone who wants to move beyond pure delivery and take ownership of security architecture, tooling decisions, and long-term IT security strategy within a high-performance, always-on environment. The Role: As Lead Security Engineer, you will act as the technical authority for security, helping to define how security is designed, implemented, and evolved across the organisation. You will work closely with Infrastructure, Cloud, and Engineering teams while advising senior stakeholders on security direction and investment. Key responsibilities include: Lead the design, build, and evolution of the firm’s security practice, setting standards, patterns, and best practices Provide deep expertise across Network Security, Cyber Security, and Cloud Security Own and develop security architecture across: Network and perimeter security Cloud platforms (primarily Azure) Identity and access management Advise on and select appropriate security tooling, ensuring the firm adopt...