Cloud Platform Security Engineer Software engineering London

Company Description

We’re Checkout.com. You might not know our name, but companies like eBay, Spotify, Klarna, Uber, and Sony do, because we’re behind many of the digital experiences you use every day. We are where the world checks out, enabling over 10 billion transactions daily for more than one billion global shoppers. Whether you want to book a holiday, order food, renew a subscription, or check out online, there’s a good chance our tech powers the payments behind the scenes. Our platform helps the most ambitious businesses deliver effortless digital experiences, at scale. If you want to do career-defining work, you’ve come to the right place. We move fast, think globally, and believe great teams are built by hiring exceptional people with conviction, curiosity, and the desire to make an impact. With 20 offices across six continents and London as our HQ, we’re shaping the future of fintech – and we’re just getting started.

The role

You will evolve Checkout.com 's security posture across our multi-cloud environments and SIEM platform. This role sits at the intersection of cloud security engineering and detection capability — responsible for both hardening the infrastructure we operate on and ensuring we can see what's happening across it. You will lead security integration projects, guide cloud engineering teams, and drive continuous improvement across monitoring and detection, including applying AI to accelerate security operations. This is not a tool-monitoring role. You are here to architect secure cloud environments, build and enhance detection logic at scale, and drive measurable improvements to our security baseline across AWS, Azure, and GCP. You will partner closely with Engineering, GRC, Technology Risk and Security Operations - defining standards, fine tuning the SIEM, and progressively taking on the most complex cloud security and detection engineering challenges across the organisation.

What you’ll be responsible for

• Cloud Security
• Secure and continuously improve our multi-cloud estate (AWS, Azure, GCP) using cloud native tooling to keep our cloud infrastructure hardened and compliant.
• Partner with Engineering and Security Operation team to make security a natural part of how we design and deliver, automating compliance checks so security scales without friction.
• Defining and enforcing cloud security architecture standards, guardrails, and policy-as-code inline with industry best practices including NIST, CIS, and PCI DSS.
• Use Wiz or equivalent CNAPP/CSPM to continuously assess, prioritise, and drive remediation of misconfigurations and vulnerabilities against CIS, NIST, and PCI DSS benchmarks.
• Security Monitoring
• Fine tune, and maintain modern SIEM platform (e.g. Sentinel) including KQL detection rules, workbooks, logging pipelines, and AI-assisted alert triage.
• Map detection coverage against MITRE ATT&CK tactics and techniques. Identify and close visibility gaps across the cloud estate.
• Maintain alignment to PCI DSS, SOC2, ISO27001 NIST, and CIS frameworks. Produce documentation and evidence to support audit and assurance activities.
• AI Security
• Design and implement guardrails for AI/LLM systems, covering data exposure, prompt injection, and model misuse risks.
• Leverage AI and automation to enhance alert investigation, enrichment, and response workflows.
• Maintain technical policies and standards for the secure use of AI tools across the organisation.

What we’re looking for

• 6+ years of hands-on experience securing AWS, Azure, and GCP environments, including Azure Policy, IAM, Infrastructure-as-code (IAC) security or other cloud native tooling.
• Experience with security tools: Microsoft Sentinel, SentinelOne, NetSkope, Flashpoint, Wiz or similar tooling.
• Strong Microsoft Sentinel expertise: KQL, detection rules, workbooks, and logging pipelines.
• Working knowledge of DLP and threat intelligence monitoring.
• Experience applying AI/ML to security workflows - automated triage, behavioural analytics, or LLM-assisted investigation.
• Understanding of AI security risks and frameworks: OWASP LLM Top 10, NIST AI RMF.
• Scripting proficiency in Python, PowerShell, or Bash for security automation.
• Strong grasp of PCI DSS, NIST CSF, SOC 2, ISO27001, CIS Benchmarks, and MITRE ATT&CK for Cloud.

Nice to have

• AZ-500, AWS Certified Security – Specialty, or equivalent cloud security certification.
• Experience integrating ATT&CK Navigator into SOC workflows.

Additional Information

Bring all of you to work. We create the conditions for high performers to thrive, through real ownership, fewer blockers, and work that makes a difference from day one. Here, you’ll move fast, take on meaningful challenges, and be recognized for the impact you deliver. It’s a place where ambition gets met with opportunity, and where your growth is in your hands. We work as one team, and we back each other to succeed. So whatever your background or identity, if you’re ready to grow and make a difference, you’ll be right at home here. It’s important we set you up for success and make our process as accessible as possible. So let us know in your application, or tell your recruiter directly, if you need anything to make your experience or working environment more comfortable.

Life at Checkout.com

We understand that work is just one part of your life. Our hybrid working model offers flexibility, with three days per week in the office to support collaboration and connection.