Platform & Security Engineer

Bourn; Greater London; On-site; GBP 80,000 - 120,000; Full time

Job summary

Bourn is building a modern cloud platform to support finance-focused products, focusing on reliability, developer experience, and user protection. You’ll help shape infrastructure, security, and tooling while aligning with evolving threats and compliance needs.

You’ll work across cloud infrastructure, IaC, Kubernetes, networking, and automated deployments, and drive security as a continuous engineering practice with measurable improvements.

Qualifications

• Experience building cloud platforms and infrastructure as code.
• Strong security engineering background with IAM, secrets, certificates.
• Experience with auditing and threat modeling is a plus.

Responsibilities

• Build and improve cloud platform and deployment pipelines.
• Strengthen security across infrastructure and services.
• Lead continuous security testing and tooling experiments.

Skills

Platform engineering

Security engineering

Cloud infrastructure

Kubernetes

Terraform

AI-assisted testing

Tools

Terraform

Kubernetes

CI/CD

Cloud providers (AWS/GCP/Azure)

Job description

At Bourn, we’re building financial products that make lending and payments simpler for businesses. Behind those experiences is a growing platform, and a team that cares about doing things thoughtfully - from reliability and developer experience to protecting the people who trust us with their money.

We’re looking for a collaborative engineer who enjoys working across infrastructure and security, sharing ideas and getting hands-on. You’ll help develop our cloud platform while continually improving how we understand, test and strengthen its security as technology and threats evolve.

What you'll be working on

Build and improve our platform: Work on cloud infrastructure, infrastructure as code, Kubernetes, networking, deployment pipelines and operational tooling. Help make our environments resilient, observable and easy for engineers to work with.

Make security a continuous engineering practice: Regularly revisit our systems as they change: review exposure, access, configuration, dependencies and application boundaries; investigate emerging risks; and follow improvements through to implementation and verification. Security is an ongoing responsibility, not a one-off audit.

Test, investigate and improve: Carry out authorised, carefully scoped assessments of our services, APIs and infrastructure. Reproduce findings, understand their real-world impact, prioritise sensibly and work with engineers to deliver lasting fixes.

Explore the next generation of security tooling: Actively seek out and experiment with emerging AI-assisted testing, agentic penetration-testing tools, automated attack-surface discovery and vulnerability analysis. Evaluate what genuinely works, understand its limitations and turn promising experiments into safe, repeatable workflows.

Build security into everyday delivery: Improve automated checks, CI/CD safeguards, monitoring and incident readiness. Make secure choices easier for the whole engineering team without slowing good work down.

The problems are interesting

A new integration changes an exposure path. A dependency develops a vulnerability. An AI testing tool finds something conventional scanning missed - or raises a convincing false positive. A system looks healthy while services cannot communicate. You’ll investigate, test assumptions and help the team make practical improvements.

How we work

We’re a small, approachable engineering team with plenty of autonomy and short feedback loops. You’ll work closely with colleagues building our products, contribute to shared platform responsibilities and have the space to explore new security approaches.

We see security as something we keep learning and improving together. New services, new AI capabilities and new attack techniques mean the work is never finished. We value thoughtful experimentation, clear evidence, sensible safeguards and people who share what they learn.

What we’re looking for

• Strong platform engineering foundations: Experience with cloud infrastructure, Terraform or similar infrastructure as code, Kubernetes, CI/CD, networking and modern automation tooling, including AI-assisted development and operations.
• Practical security engineering: Familiarity with identity and access, secrets, certificates, cloud and API security, vulnerability management and common application security risks.
• Curiosity about modern offensive-security tooling: Hands-on interest in security testing, including emerging AI-powered and agentic tools. You enjoy trying new approaches, comparing results and validating findings rather than taking tool output at face value.
• A continuous-improvement mindset: You keep up with new vulnerabilities, techniques and tools; make time for experimentation; and look for ways to incorporate useful discoveries into everyday engineering.
• Ownership and sound judgement: Comfortable tracing a problem from discovery to remediation, assessing risk and knowing when to involve specialist external testers.
• Collaborative communication: Able to explain technical risks constructively, partner with application engineers and balance security, reliability and developer productivity.

You'd enjoy this role if...

• You enjoy building and running infrastructure as much as making it safer.
• You are excited to experiment with new AI security and penetration-testing tools.
• You like validating findings and making fixes, not just producing reports.
• You enjoy learning continuously and helping colleagues adopt better practices.
• You want to help protect financial products used by real businesses.

Interview Process

• Introductory call– a video or phone call with our VP Engineering to get to know each other
• Technical interview– a coding challenge with a member of the engineering team
• Values and ways of working– a conversation with our Chief of Staff
• Founder call– a chat with our founder about Bourn’s vision and where we’re heading
• Offer– if it’s a match, we’ll make you an offer