Senior Backend Engineer: Python APIs & Distributed Systems in London

We are looking for a Senior Backend Engineer to join our London-based engineering team. This is a hands‑on, high‑impact role where you will help design and build the core services, APIs, and integrations that power our security platform, working closely with a globally distributed team. You will work closely with product managers, security analysts and fellow engineers to deliver reliable, scalable and observable systems. Alongside building high‑quality software, you will also play a key role in shaping how the team uses modern AI coding tools to improve speed and productivity without compromising on quality, security or maintainability. This role is ideal for someone who enjoys working on distributed systems, takes pride in clean and well‑tested code, and wants to contribute to a technically strong and collaborative engineering environment. This role is hybrid in our office in Blackfriars London.

About SecurityHQ

SecurityHQ is a global cybersecurity company. Our specialist teams design, engineer and manage solutions that do three things: Promote clarity and trust in a complex world. Build momentum around improving security posture. And increase the value of cybersecurity investment within organizations. Free from limitations, and inclusive of all requirements, we focus on defending today, while mitigating the risks of tomorrow. And into the future. Our solutions are tailored to our customers and their unique context. Around the clock, 365 days per year, our customers are never alone. SecurityHQ – We’re focused on engineering cybersecurity, by design.

What You’ll Be Responsible For

• Design, build and operate production‑grade Python microservices using FastAPI and Django where appropriate, applying clean architecture and modern design principles.
• Develop resilient APIs and distributed systems using async patterns and domain‑driven design approaches.
• Own services end‑to‑end, from design through to deployment and production support.
• Build and maintain event‑driven workflows, designing for idempotency, retries, error handling and system resilience.
• Develop integrations and messaging patterns that ensure scalable and reliable communication across services.
• Deploy and operate services on AWS using technologies such as EKS, PostgreSQL, messaging systems and object storage.
• Manage infrastructure through Terraform and contribute to a GitOps‑based deployment model using GitHub Actions and FluxCD.
• Work closely with frontend engineers in an Angular microfrontend environment to design clean, well‑versioned and user‑friendly API contracts.
• Participate in architecture design, code reviews and technical discussions, contributing to overall engineering quality and standards.

Quality, Testing & Observability

• Build and maintain comprehensive test suites including unit, integration, contract and end‑to‑end testing.
• Ensure services are fully instrumented with logging, metrics and tracing to support observability in production.
• Treat testing, monitoring and CI signals as essential components of delivery.

Agile Delivery & Continuous Improvement

• Contribute to agile ceremonies including refinement, estimation and retrospectives.
• Support continuous improvement across engineering practices, ways of working and use of AI‑assisted development tools.

Technical Experience & Skills

• 5 or more years of backend engineering experience with Python as a primary language, delivering and operating services in production environments.
• Strong experience with FastAPI or Django, including API design, async patterns, dependency management and authentication and authorisation.
• Solid understanding of microservices and distributed systems, including service boundaries, resilience patterns and event‑driven design.
• Strong PostgreSQL experience, including schema design, indexing and performance optimisation.
• Hands‑on experience with AWS and containerised workloads, ideally using Kubernetes or EKS.
• Experience with CI and CD pipelines, particularly GitHub Actions and GitOps approaches.
• Strong foundations in testing, observability, security and technical documentation.
• Excellent written communication skills across design documentation, PRs and incident reporting.