Capital.com's Product Security team protects our web and mobile applications, infrastructure, and external perimeter in a highly regulated environment. As Senior/Staff Application Security Engineer, you will raise the bar for application security across the organisation. This role is measured by leverage: how well you design, automate, and scale security processes so that many engineering teams can build securely by default.
You will lead security architecture reviews and threat modelling, increasingly with the help of AI tooling, and turn one-off security work into repeatable, self-service capabilities. The role combines deep hands-on offensive and defensive security expertise with the engineering mindset needed to automate at scale. You will work closely with development, QA, DevOps, and platform teams.
Responsibilities:
Requirements:
Experience:
- 5+ years in application or product security, or equivalent depth, with a track record of senior or staff-level impact
- Demonstrable experience leading security architecture reviews and threat modelling (e.g. STRIDE, attack trees, data-flow analysis) across multiple teams or products
- Proven ability to automate and scale security processes by building tooling, integrations, and self-service workflows that reduce manual effort
Technical:
- Strong hands-on security testing skills, including code review and web, mobile, and API application security assessments, as well as the ability to triage and validate external vulnerability reports and bug bounty submissions
- Strong software engineering ability in at least one language (e.g. Python, Go, JavaScript), with the ability to build automation, not just scripts
- Deep understanding of the OWASP Top Ten, secure design, and secure coding best practices
- Experience with SAST, DAST, SCA, and vulnerability management platforms, and integrating them into CI/CD
- Strong understanding of modern application architectures: REST APIs, microservices, cloud-based systems, and containers
- Practical experience applying AI and LLM tooling to security work, or clear enthusiasm and aptitude to do so
Collaboration:
- Excellent communication and influencing skills: you can explain security concepts to technical and non-technical stakeholders and drive change without direct authority
- A self-starter who enjoys solving complex problems, building leverage through automation, mentoring others, and strengthening security culture
Nice to have:
- Experience securing the AI harness: hardening LLM and agent pipelines, prompts, tool and MCP integrations, and model endpoints against prompt injection, data leakage, and insecure agent actions
- Experience securing Kubernetes, including cluster hardening, RBAC, network policies, admission control, workload isolation, and image and supply-chain security
- Experience securing AWS infrastructure, including IAM, network and account architecture, key and secret management, and CSPM
- Experience building AI-assisted security tooling or internal self-service security platforms
- Experience mentoring or technically leading a security team
- Offensive or advanced security certifications such as OSAI, OSEP, OSCP, or OSWE
What you'll get in return:
- You will join the company, that cares about work and life balance
- Annual Bonus based on the performance review cycle
- Generous Annual Leave Policy
- Medical Insurance and Pension fund, with additional benefit packages based on the location
- Hybrid working model (3 days from our modern office and 2 days fully remotely)
- Comprehensive Workation Policy with 30 more remote days available.
- Possibility of taking two additional days of paid leave per year to dedicate to volunteering efforts.
