Senior Software Engineer - Login Platform London, GBR Posted today

The Login Platform group covers all aspects of user authentication and experience across Terminal and Enterprise (non-Terminal) workflows. This includes teams that manage Bloomberg’s Single Sign-On (SSO), Multi-Factor Authentication, user login experience, and the sessions platform used to propagate authentication and authorization context throughout the Bloomberg ecosystem. Sessions are the backbone of authorization decisions across Bloomberg. They are created from entry points including the Terminal, Mobile, Enterprise applications, Web, and more. These sessions need to include the correct entitlements, customer data, and security context so that application teams can make the accurate entitlement decisions.

We’re evolving our session and authorization infrastructure to support AI agents, MCP-based integrations, and machine-to-machine workflows across Bloomberg systems. We are hiring Senior Software Engineers for two closely related teams in London focused on session infrastructure and session lifecycle management.

Where we sit: We’re part of Login Platform within the Platform Security organization, operating deep in the infrastructure stack. Our teams own the framework that orchestrates sessions enrichment flows, while data-owning teams provide and manage the underlying datasets. Almost every business unit at Bloomberg depends on our platform to make authorization and access-control decisions. Our software is critical to maintaining Bloomberg’s reliability, compliance, and continued growth. Because of our position in the stack, we enforce security not only for others, but for ourselves as well.

What you’ll do: As a Senior Software Engineer, you’ll play a key role in shaping and scaling the infrastructure that powers session creation, enrichment and authorization across Bloomberg. You will:

• Design, build, and optimize low-latency, multi-threaded backend systems that handle session and authorization data at scale.
• Collaborate with multiple Engineering and Product teams to deliver a reliable and secure login experience.
• Contribute to architectural decisions and long-term technical strategy for the Login Platform.
• Improve tooling, observability, scalability, and performance across critical infrastructure services.
• Explore and champion new ideas to evolve our systems responsibly over time.

Engineers on the team are involved throughout the software lifecycle, including design, deployment, observability, incident response, and long-term platform evolution.

Our technologies: We work primarily in C++ and some Python, running mostly on Linux, with continued support for Solaris clients until full migration is complete. Because we sit deep in the infrastructure stack, you’ll often need to balance innovation with compatibility, designing modern, robust solutions that coexist with legacy systems.

You’ll need to have:

• Strong software engineering experience in C++, ideally building backend, infrastructure, platform, or systems-level software.
• Experience designing, building, or operating distributed backend systems, ideally in high-availability, low-latency, or infrastructure-heavy environments.
• Strong experience designing and building multi-threaded or concurrent applications.
• Experience owning software across the full lifecycle, including design, implementation, testing, deployment, observability, incident response, and long-term evolution.
• Ability to make pragmatic system design decisions across performance, scalability, reliability, maintainability, and compatibility constraints.
• An eagerness to understand a large, non-trivial stack and propose incremental improvements without compromising reliability or security.
• Strong communication and collaboration skills, with the ability to work effectively across Engineering, Product and platform-dependent teams.
• A Degree in Computer Science, Engineering, Mathematics, similar field of study or equivalent work experience.

We’d love to see:

• Background in authentication, authorization, identity, access control, entitlement systems, SSO, MFA, session management, or security-sensitive infrastructure.
• Familiarity with systems that propagate authentication, authorization, entitlement, or security context across distributed services.
• A track record of building low-latency, reliable backend or infrastructure services.
• Hands-on involvement in improving observability, scalability, performance, reliability, or operational tooling for production systems.
• Exposure to platform teams that support multiple internal product or application teams.
• Experience working across multiple business units or products, with an understanding of their operational and integration challenges.

If indicated, please note that years of experience are a guide; we will consider applications from all candidates who can demonstrate the skills necessary for the role.

Bloomberg is an equal opportunity employer and we value diversity at our company. We do not discriminate on the basis of age, ancestry, color, gender identity or expression, genetic predisposition or carrier status, marital status, national or ethnic origin, race, religion or belief, sex, sexual orientation, sexual and other reproductive health decisions, parental or caring status, physical or mental disability, pregnancy or parental leave, protected veteran status, status as a victim of domestic violence, or any other classification protected by applicable law. Bloomberg is a disability inclusive employer. Please let us know if you require any reasonable adjustments to be made for the recruitment process. If you would prefer to discuss this confidentially, please email amer_recruit@bloomberg.net