At a Glance
- Tasks: Own and develop the core product platform for AI security, building APIs and SDKs.
- Company: Refractal, a pioneering AI security company tackling modern threats.
- Benefits: Competitive salary, equity, performance bonuses, and visa sponsorship.
- Other info: Work in a dynamic London-based environment with opportunities for global talent.
- Why this job: Make a real impact in AI security with direct influence on product and architecture.
- Qualifications: Strong backend experience, especially with HTTP APIs, Python, and FastAPI.
The predicted salary is between 60000 - 115000 £ per year.
Refractal is an AI security company building the infrastructure organisations need to defend against autonomous AI threats. 2026 has shown that generally capable intelligence is here. The challenge now is modernising security to stop AI-enabled threats, whether they come from internal agents going rogue or from attackers using AI to become more dangerous.
Responsibilities:
- Own the core product platform from its external interfaces through the service and data layers.
- Build the APIs and SDKs that connect Refractal to customer systems, along with the services, identity controls, and event contracts behind them.
- Work directly with the founders and early customers to turn operational security needs into simple, reliable platform interfaces and operator tools.
- Own stable, versioned platform APIs and SDKs, including client interfaces, compatibility rules, documentation, and examples.
- Build FastAPI services for enforcement decisions, evidence, policies, and red-team results.
- Design authentication, sessions, API keys, authorisation, and rigorous multi-tenant isolation.
- Build data and event interfaces, real-time streams, and a tamper-evident audit ledger.
- Create customer onboarding, policy integration, and operator dashboard workflows.
- Own testing and deployment across API compatibility, browser smoke tests, Cloud Run, and Cloud SQL.
Requirements:
- A product-minded platform engineer who makes complex systems clear and predictable and takes ownership from the data model to the customer integration.
- Strong backend experience with HTTP APIs; Python and FastAPI experience is preferred.
- Experience with observability, tracing, relational databases, and database migrations.
- Sound judgement around API design, versioning, SDKs, and compatibility.
- A strong understanding of authentication, authorisation, API keys, and multi-tenant access control.
- Good JavaScript and React skills for building operator-facing product surfaces.
- The ability to work independently and own technically uncertain customer problems.
Conditions:
- Competitive salary, meaningful equity, and a performance-linked bonus.
- Direct influence over the product, architecture, engineering standards, and company direction.
- Real, high-consequence AI deployments rather than purely synthetic environments.
- London-based, in-person work, with UK Skilled Worker visa sponsorship and support for Global Talent applications.
- Compensation Range: £60K - £115K
Platform engineer in AI security in London employer: Refractal
Refractal is an exceptional employer for those looking to make a significant impact in the field of AI security. As a founding AI Research Engineer, you will join a dynamic team with unparalleled expertise from prestigious institutions and have the opportunity to shape the future of AI safety while enjoying competitive compensation, equity, and a culture that fosters innovation and collaboration in London. With direct access to high-stakes projects and a clear path for career advancement, Refractal offers a unique environment for ambitious individuals eager to drive real-world change.
StudySmarter Expert Advice🤫
We think this is how you could land Platform engineer in AI security in London
✨Join Local Tech Meetups
Get out there and mingle with fellow developers by joining local tech meetups. It’s a fantastic way to meet people who might be working at Refractal or know someone who does. Plus, you can pick up some trendy tech skills and trends while you're at it!
✨Contribute to Open Source Projects
Show off your coding chops by jumping into open-source projects. Not only does this give you practical experience, but it also gets you noticed in the dev community. You'll create a killer portfolio that speaks volumes about your skills to Refractal.
✨Tap into Online Developer Communities
Don’t underestimate the power of online developer communities like GitHub, Stack Overflow, and even Reddit. Participate in discussions, share your projects, and build your visibility. We can often find opportunities through these channels that can lead to a full-time gig at companies like Refractal.
✨Explore Job Boards Specifically for Tech Roles
Keep your eyes peeled on job boards that focus on tech roles. Sites like TechCareers or Stack Overflow Jobs can often have listings for companies like Refractal that might not show up on broader job sites. Make it a habit to check these regularly, and don’t hesitate to apply directly through our website!
We think you need these skills to ace Platform engineer in AI security in London
Some tips for your application 🫡
Show off your coding skills:When applying for a software engineering role, it's super important to showcase your coding skills. Make sure your CV includes your tech stack, any relevant programming languages you’re comfortable with, and examples of projects you've worked on. If you have a GitHub profile, link it up! We love to see code in action.
Tailor your portfolio:For a full-time role, we’d expect to see some solid examples of your work in your portfolio. Make sure to include at least two or three projects that highlight your problem-solving skills and your ability to work with different technologies. Focus on the projects that are most relevant to the position at Refractal.
Craft a killer cover letter:Your cover letter is your chance to stand out—make it personal! Explain why you want to work at Refractal and how your skills align with the role. Show us your passion for software development. We dig enthusiastic candidates who understand the value of collaboration and continuous learning!
Be clear and concise:When it comes to writing your CV and cover letter, clarity is key. Avoid jargon that could confuse us and stick to simple, direct language. Highlight your achievements with quantifiable results where possible, and keep everything easy to read. A well-organised application goes a long way!
How to prepare for a job interview at Refractal
✨Brush Up on Your Coding Skills
For a full-time software engineering role, it's crucial that we stay sharp with our coding abilities. Expect technical questions that might involve solving problems on the spot or discussing algorithms. Practise on platforms like LeetCode or HackerRank to get comfortable with the types of questions that often come up.
✨Know Your Tools and Frameworks
Make sure we’re well-acquainted with the tools and technologies listed in the job description. Familiarise ourselves with any specific frameworks or programming languages mentioned. If Refractal uses React or Node.js, for instance, be ready to discuss how we’ve used them in previous projects or coursework.
✨Showcase Your Projects
Bring along a portfolio that highlights our best work. This could be code samples, GitHub repositories, or any side projects we’ve built. Make sure we can talk through our thought process for each project, especially the challenges we faced and how we solved them—this shows our problem-solving skills in action.
✨Prepare for Behavioural Questions
While technical skills are key, full-time positions also require cultural fit. Be ready to discuss our previous experiences and how we handle teamwork, conflict, and deadlines. Brush up on the STAR method—Situation, Task, Action, Result—to clearly articulate our past experiences when discussing how we've contributed to a team.
