Jobs in United Kingdom

Security Lead in United Kingdom

139 active opportunities · Updated October 2026

Explore current security lead jobs across United Kingdom. Filter by work mode, employment type, experience, department, date posted and distance.

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📍 London, London, United Kingdom· Full-time
✓ Quality checkedCompany trend -100%

Who are we? Cohere is the leading security-first enterprise AI company. We build cutting-edge foundation AI models and end-to-end products that are designed to solve real-world business problems. We’re training and deploying frontier models for enterprises who are building AI systems. We believe that our work is instrumental to the widespread adoption of AI and we are looking for folks that want to be part of that. We obsess over what we build. Each one of us is responsible for contributing to increasing the capabilities of our models and the value they drive for our customers. Cohere is a team of researchers, engineers, designers, and more, who are all passionate about their craft. We are a global technology company headquartered in Toronto with key offices in London, New York City, San Francisco, Montreal, Paris, Berlin and Seoul. Join us! Why this role? As a Performance Engineer in the Pre-Training team you will be responsible for optimizing the performance of our advanced language models and systems. Their primary focus is on improving key model training metrics, such as training throughput, ensuring high accelerator utilization. The team combines expertise in software engineering, machine learning, and low-level kernel design and development to design robust systems and enhance model performance. You will work on identifying and removing performance bottlenecks, develop cutting-edge training and profiling tools to help Cohere's mission of providing efficient and reliable language understanding and generation capabilities and drive innovation in the field of natural language processing. Note: We have offices in London, Toronto, New York and San Francisco, but we’re also remote-friendly! This team operates primarily between ET to CET time zones, so we’re seeking candidates in locations that align with these hours for effective collaboration. As a Member of Technical Staff, you will: Design and write high-performant and scalable software for training. Understand a

PythonGitMachine LearningAI
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📍 London, London, United Kingdom· Full-time
✓ Quality checkedCompany trend -100%

Who are we? Cohere is the leading security-first enterprise AI company. We build cutting-edge foundation AI models and end-to-end products that are designed to solve real-world business problems. We’re training and deploying frontier models for enterprises who are building AI systems. We believe that our work is instrumental to the widespread adoption of AI and we are looking for folks that want to be part of that. We obsess over what we build. Each one of us is responsible for contributing to increasing the capabilities of our models and the value they drive for our customers. Cohere is a team of researchers, engineers, designers, and more, who are all passionate about their craft. We are a global technology company headquartered in Toronto with key offices in London, New York City, San Francisco, Montreal, Paris, Berlin and Seoul. Join us! Why this role? As a Member of Technical Staff in Data Analysis and Evaluation, you will play a pivotal role in ensuring the quality, reliability, and performance of our large language models (LLMs). Your primary focus will be on designing and conducting data collection tasks, assessing and evaluating dataset quality, and analysing the robustness and generalisability of our models. You will work closely with cross-functional teams, including researchers, engineers, and data annotators, to conduct data-driven decision-making and improve the overall effectiveness of our AI systems. This role combines expertise in statistics, experimental design incl. human annotators, and machine learning to ensure that our models are trained on high-quality data and perform reliably across diverse scenarios. You will contribute to Cohere’s mission of advancing AI by ensuring our systems are robust, scalable, and impactful. Please Note: We have offices in London, Paris, Toronto, San Francisco, and New York, but we also embrace being remote-friendly! There are no restrictions on where you can be located for this role. As a Member of Technical Staff

PythonGitRestMachine Learning
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📍 London, London, United Kingdom· Full-time
✓ Quality checkedCompany trend -100%

Who are we? Cohere is the leading security-first enterprise AI company. We build cutting-edge foundation AI models and end-to-end products that are designed to solve real-world business problems. We’re training and deploying frontier models for enterprises who are building AI systems. We believe that our work is instrumental to the widespread adoption of AI and we are looking for folks that want to be part of that. We obsess over what we build. Each one of us is responsible for contributing to increasing the capabilities of our models and the value they drive for our customers. Cohere is a team of researchers, engineers, designers, and more, who are all passionate about their craft. We are a global technology company headquartered in Toronto with key offices in London, New York City, San Francisco, Montreal, Paris, Berlin and Seoul. Join us! Role Overview: Building AI agents that can assist with any kind of enterprise work is a challenging, open-ended problem. One key piece of solving it is replicating real work environments as realistically as possible - filling them with hard tasks to solve, creating plausible input data, and defining clear rewards for completing the work the right way. We build many of these reinforcement learning (RL) environments, then drop our agents into them to evaluate or train them. In this role, you are responsible for creating these RL environments, running AI agents inside them, and improving both the agents and the environments in the process. The results reach customers, whose feedback feeds back in - and the agent/environment improvement loop continues. Key Responsibilities: There are many open problems in this space. As a Member of Technical Staff, RL Environments, you will: Build new RL environments targeting different agentic capabilities and industry areas Train and evaluate agents in those environments Make all the pieces work together: tasks, data, tool implementations, and verifiers Work across modeling and product to identify

C
📍 London, London, United Kingdom· Full-time
✓ Quality checkedCompany trend -100%

Who are we? Cohere is the leading security-first enterprise AI company. We build cutting-edge foundation AI models and end-to-end products that are designed to solve real-world business problems. We’re training and deploying frontier models for enterprises who are building AI systems. We believe that our work is instrumental to the widespread adoption of AI and we are looking for folks that want to be part of that. We obsess over what we build. Each one of us is responsible for contributing to increasing the capabilities of our models and the value they drive for our customers. Cohere is a team of researchers, engineers, designers, and more, who are all passionate about their craft. We are a global technology company headquartered in Toronto with key offices in London, New York City, San Francisco, Montreal, Paris, Berlin and Seoul. Join us! Why This Role? There's so much we can tell you about this role and why we're excited about it, but to keep it brief, here are the top things you need to know. We're excited to receive your application and talk to you soon! TL:DR: We're hiring an HR Business Partner to work with our Modelling organization, supporting Research and Engineering through an extraordinary phase of growth. A role that matters. HRBPs are central to our People model - trusted by leaders, brought into important organizational challenges, and expected to have a point of view. A front-row seat to AI. Work alongside exceptional researchers, engineers, and leaders at the forefront of AI - some of the most talented and in-demand people in the industry. A chance to build. We're building the foundations of our People function at scale, with plenty of white space and latitude to shape how we work rather than inherit established playbooks. Real ownership, with a built-in partner. You'll own relationships and priorities while working in an HRBP pod - giving you someone to bounce ideas off, share the load when needed, and provide seamless cover when you're away. An e

GitAIGoRust
C
📍 United Kingdom· Full-time
✓ High-confidence listingCompany trend -100%
Quick readStrong listing-quality and freshness signals

Who are we? Cohere is the leading security-first enterprise AI company. We build cutting-edge foundation AI models and end-to-end products that are designed to solve real-world business problems. We’re training and deploying frontier models for enterprises who are building AI systems. We believe that our work is instrumental to the widespread adoption of AI and we are looking for folks that want to be part of that. We obsess over what we build. Each one of us is responsible for contributing to increasing the capabilities of our models and the value they drive for our customers. Cohere is a team of researchers, engineers, designers, and more, who are all passionate about their craft. We are a global technology company headquartered in Toronto with key offices in London, New York City, San Francisco, Montreal, Paris, Berlin and Seoul. Join us! About the Role We're looking for an Engineering Manager to lead our Deployment Engineering team in EMEA. This isn't a typical management role — we need someone who leads from the front, gets their hands dirty, and drives impact. You'll manage a team of Forward Deployed Engineers who are on the front lines of deploying Cohere's North platform into customer environments. You should be ready to be a force to be reckoned with. Location: UK (can be remote but based in UK) What You'll Do Lead and mentor a team of Forward Deployed Engineers across EMEA Drive end-to-end deployment of North in private cloud and on-premises environments Take ownership of customer success from technical implementation through delivery Collaborate closely with Product, Engineering, and Sales to shape how we deliver AI to enterprises Mentor your team on cloud infrastructure, Kubernetes, and enterprise-grade deployments Optimize performance for OpenSearch, databases, and other K8s services Define scaling guidelines for GPU and CPU compute resources Build processes & technology that scales — we're growing fast. What We're Looking For 5+ years of experience

AWSAzureGCPKubernetes
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📍 London, London, United Kingdom· Full-time
✓ Quality checkedCompany trend -100%

Who are we? Cohere is the leading security-first enterprise AI company. We build cutting-edge foundation AI models and end-to-end products that are designed to solve real-world business problems. We’re training and deploying frontier models for enterprises who are building AI systems. We believe that our work is instrumental to the widespread adoption of AI and we are looking for folks that want to be part of that. We obsess over what we build. Each one of us is responsible for contributing to increasing the capabilities of our models and the value they drive for our customers. Cohere is a team of researchers, engineers, designers, and more, who are all passionate about their craft. We are a global technology company headquartered in Toronto with key offices in London, New York City, San Francisco, Montreal, Paris, Berlin and Seoul. Join us! Why This Role? We're seeking an experienced Program Manager to join Cohere's customer-facing Program Management team, with a focus on UK public sector and defence accounts. This is a highly specialised role requiring an individual who understands technical program delivery, the technical complexity of frontier AI models and the unique requirements of government and defence organisations. You will be the critical bridge between our cutting-edge AI capabilities and the specific needs of UK Government and defence organisations. You'll navigate complex procurement processes, stringent security requirements, data sovereignty concerns, and regulatory compliance while ensuring our customers successfully deploy and scale our AI solutions. In this role, you'll collaborate with our Strategic Customer team, Applied ML (AML) Engineering, Forward Deployed Engineering (FDE), Platform, Product, and Go-to-Market teams, serving as the technical program lead and trusted advisor for our most sensitive and high-impact government engagements. Location: UK Security Clearance: Active Top Secret clearance preferred; candidates with Active Secret cleara

AWSAzureGitAI
C
📍 United Kingdom· Full-time
✓ Quality checkedCompany trend -100%

Who are we? Cohere is the leading security-first enterprise AI company. We build cutting-edge foundation AI models and end-to-end products that are designed to solve real-world business problems. We’re training and deploying frontier models for enterprises who are building AI systems. We believe that our work is instrumental to the widespread adoption of AI and we are looking for folks that want to be part of that. We obsess over what we build. Each one of us is responsible for contributing to increasing the capabilities of our models and the value they drive for our customers. Cohere is a team of researchers, engineers, designers, and more, who are all passionate about their craft. We are a global technology company headquartered in Toronto with key offices in London, New York City, San Francisco, Montreal, Paris, Berlin and Seoul. Join us! Role Overview Cohere has a strong AI narrative, the most deployable product, and a CEO who co-authored the foundational paper of modern AI. The company is positioned to become the transatlantic leader in sovereign AI for enterprise and government, and needs a storytelling engine to deliver that story at scale. This role sits within the team that is building that engine. In this cross functional role, you will stand up our PR and Communications function in the EMEA region. You'll partner with the global Corporate Communications team to create regional plans that fuel our growth among governments and enterprises in the most highly-regulated industries. You’ll work with cross functional teams to ensure regional messaging is culturally relevant and effective for customers, partners, and employees in each region. This is a rare opportunity to build a comprehensive EMEA communications function at a fast-growing company in the most dynamic space in technology. This is a role for someone who likes to take big swings – and have fun doing it – where no job is too big or too small. Key Responsibilities Build a PR and Communications functio

GitRestAIGo
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📍 London, London, United Kingdom· Full-time
✓ Quality checkedCompany trend -100%

Who are we? Cohere is the leading security-first enterprise AI company. We build cutting-edge foundation AI models and end-to-end products that are designed to solve real-world business problems. We’re training and deploying frontier models for enterprises who are building AI systems. We believe that our work is instrumental to the widespread adoption of AI and we are looking for folks that want to be part of that. We obsess over what we build. Each one of us is responsible for contributing to increasing the capabilities of our models and the value they drive for our customers. Cohere is a team of researchers, engineers, designers, and more, who are all passionate about their craft. We are a global technology company headquartered in Toronto with key offices in London, New York City, San Francisco, Montreal, Paris, Berlin and Seoul. Join us! About the Role We're seeking a Senior/Staff Engineer to build and maintain the automation infrastructure that powers the development cycles of our North platform. This engineer will design and implement robust automation systems that enable engineers to efficiently test and validate changes across diverse environments and configurations. This role sits at the intersection of infrastructure and standards. You'll build the systems, frameworks, and culture that allow the rest of engineering to own quality themselves; improving and extending our testing platform by creating the infrastructure that allows engineers to write and execute tests, and enable every engineering team to ship with more confidence. Key Responsibilities Design and implement automation pipelines that support comprehensive testing across multiple environments with varying feature flags and realistic customer data profiles Create intelligent testing agents that simulate real user behavior to validate different configuration combinations Develop and maintain GitHub workflows and actions to automate testing, deployment, and validation processes Manage and optimize H

TypeScriptPythonAWSAzure
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📍 London, London, United Kingdom· Full-time
✓ Quality checkedCompany trend -100%

Who are we? Cohere is the leading security-first enterprise AI company. We build cutting-edge foundation AI models and end-to-end products that are designed to solve real-world business problems. We’re training and deploying frontier models for enterprises who are building AI systems. We believe that our work is instrumental to the widespread adoption of AI and we are looking for folks that want to be part of that. We obsess over what we build. Each one of us is responsible for contributing to increasing the capabilities of our models and the value they drive for our customers. Cohere is a team of researchers, engineers, designers, and more, who are all passionate about their craft. We are a global technology company headquartered in Toronto with key offices in London, New York City, San Francisco, Montreal, Paris, Berlin and Seoul. Join us! Why this role? North is Cohere's cutting-edge AI workspace platform, designed to revolutionize the way enterprises utilize AI. It offers a secure and customizable environment, allowing companies to deploy AI while maintaining control over sensitive data. North integrates seamlessly with existing workflows, providing a trusted platform that connects AI agents with workplace tools and applications. The Agents & Automations team builds the platform inside North that lets customers create AI-powered workflows. Some of these workflows are structured automations, such as routing requests, keeping systems up-to-date, or triggering approvals. Others are more flexible agents that can gather context, use tools, make decisions, and take action across enterprise systems. As an engineer on this team, you will help build the core platform that makes this possible: the workflow builder, execution engine, integrations, debugging tools, observability, evaluation systems, and feedback loops that help customers understand and improve what they deploy. This is broad product engineering work across frontend, backend, and AI-powered systems. The

TypeScriptPythonReactKubernetes
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📍 London, London, United Kingdom· Full-time
✓ Quality checkedCompany trend -100%

Who are we? Cohere is the leading security-first enterprise AI company. We build cutting-edge foundation AI models and end-to-end products that are designed to solve real-world business problems. We’re training and deploying frontier models for enterprises who are building AI systems. We believe that our work is instrumental to the widespread adoption of AI and we are looking for folks that want to be part of that. We obsess over what we build. Each one of us is responsible for contributing to increasing the capabilities of our models and the value they drive for our customers. Cohere is a team of researchers, engineers, designers, and more, who are all passionate about their craft. We are a global technology company headquartered in Toronto with key offices in London, New York City, San Francisco, Montreal, Paris, Berlin and Seoul. Join us! Why this role? North is Cohere's cutting-edge AI workspace platform, designed to revolutionize the way enterprises utilize AI. It offers a secure and customizable environment, allowing companies to deploy AI while maintaining control over sensitive data. North integrates seamlessly with existing workflows, providing a trusted platform that connects AI agents with workplace tools and applications. The Agents & Automations team builds the platform inside North that lets customers create AI-powered workflows. Some of these workflows are structured automations, such as routing requests, keeping systems up-to-date, or triggering approvals. Others are more flexible agents that can gather context, use tools, make decisions, and take action across enterprise systems. As an engineer on this team, you will help build the core platform that makes this possible: the workflow builder, execution engine, integrations, debugging tools, observability, evaluation systems, and feedback loops that help customers understand and improve what they deploy. This is broad product engineering work across frontend, backend, and AI-powered systems. The

TypeScriptPythonReactKubernetes
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📍 London, England, United Kingdom· Full-time
✓ High-confidence listing
Quick readStrong listing-quality and freshness signals

Skeletons, lasers, tattoo buses — the Torq brand grabs attention like nothing else in cybersecurity. And we're growing like crazy, backed by Series D funding, 200% employee growth, and 300% revenue growth. Fueling Torq's momentum is our game-changing AI SOC platform, backed by a team and culture that makes Torq one of Forbes' Best Startup Employers in America, and a Business Insider 'startup to bet your career on'. Life at Torq is all gas, no brakes. We're a team of relentless, collaborative go-getters pushing the boundaries of what's possible for security automation. Every role is an essential driver of Torq's success as the AI-native autonomous SecOps platform of choice for security teams across the Fortune 500. Over the past year, we've built one of the fastest-growing Enterprise Sales organizations in EMEA. Now we're looking for a hands-on Regional Sales Director to lead our Western Europe business across the UK, Ireland, France, Benelux, and Northern Europe. This isn't a role for someone who wants to manage from behind a dashboard. We're looking for a leader who enjoys being in the field, building pipeline alongside the team, partnering with customers, and helping experienced Enterprise sellers win bigger. Location: London, UK (preferred) What you'll do Lead, coach, and develop a team of Enterprise Account Executives across Western Europe. Own the regional sales strategy and execution to achieve ambitious growth targets. Drive pipeline generation, forecasting, operational excellence, and accurate sales execution. Partner closely with customers, Sales Engineers, Marketing, and Channel teams to accelerate strategic opportunities. Support the team throughout complex enterprise sales cycles, from prospecting to closed deals. Identify new business opportunities and expand Torq's presence across the region. Recruit, hire, and develop top-performing Enterprise sales talent. Represent Torq at customer meetings, executive briefings, and industry events. Foste

AIGoExcelMarketing
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📍 London, England, United Kingdom
✓ High-confidence listing
Quick readStrong listing-quality and freshness signals

Altana is the network for trusted trade. Our AI-powered product network empowers governments and businesses to build a more resilient and secure global economy while keeping trade flowing. The Role: Vertical Technology Lead, Policy & National Security Altana’s mission is to power a new era of globalization organized around trusted networks. Nowhere is that mission more consequential — or more demanding — than in the policy and national security community, where the questions our customers bring us are matters of sovereignty, security, and how a nation understands the networks it depends on. These are the hardest programs we run. The technical bar is high and it keeps rising: the biggest opportunities are won, kept, and expanded on the strength of the technical work itself — sometimes on technical capability alone. As these engagements grow, so does the machinery large government partners expect from a serious partner: program management, delivery cadence, contractual rigor, accreditation. Left unmanaged, that machinery swamps the very people whose job is to architect and build. We’re changing how we deliver so it doesn’t. Large and strategic accounts are staffed with dedicated Implementation Delivery Managers (IDMs) who carry the program, project, and delivery-management load — and, as an account grows more complex, we trade up the team to meet it. That frees the technical leadership of the vertical to do what only it can do: hold the architecture bar, win the technical argument, and drive the last mile of product where the mission needs something that doesn’t exist yet. As Vertical Technology Lead for Policy & National Security, you own the technical outcomes for the vertical end-to-end. You are the senior technical counterpart to the vertical’s commercial leadership — setting the technical approach that wins business, owning the solution architecture and delivery that turns wins into mission outcomes, and leading the team that does the work. This is a UK-b

PythonSQLAWSAzure
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Licensed UK sponsor. This company appears in the UK worker sponsor register. A license does not mean this role offers sponsorship.
📍 London, United Kingdom· Full-time
✓ Quality checkedCompany trend -100%

Synthesia is the world’s leading AI video platform for business, used by over 90% of the Fortune 100. Founded in 2017, the company is headquartered in London, with offices and teams across Europe and the US. As AI continues to shape the way we live and work, Synthesia develops products to enhance visual communication and enterprise skill development, helping people work better and stay at the center of successful organizations. Following our recent Series E funding round, where we raised $200 million, our valuation stands at $4 billion. Our total funding exceeds $530 million from premier investors including Accel, NVentures (Nvidia's VC arm), Kleiner Perkins, GV, and Evantic Capital, alongside the founders and operators of Stripe, Datadog, Miro, and Webflow. Location: Europe remote or London hybrid About the role: As our engineering and research organisation grows, so does the complexity of securing it. Our Application Security team is at the forefront of that challenge — building AI-native security tooling, embedding security into the development lifecycle at scale, and finding ways to make a small, highly capable team punch well above its weight. We're looking for an Engineering Manager to lead and grow the AppSec team. This is not a coordination role. You'll be leading a team of exceptionally senior and staff-level engineers who are deeply self-directed and technically excellent. To earn their trust and enable their best work, you'll need to be genuinely close to the craft — able to engage at depth on threat modelling, agentic security tooling, SDLC design, and application risk. You'll also own AppSec strategy and be accountable for how the function scales alongside a product organisation that is growing fast and leaning heavily into AI-assisted development. Important note: Anyone working as a manager within the Infosec team will need to follow the Infosec Team Management Tenets . Key Responsibilities: Lead, support, enable and grow the AppSec team — owning hirin

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📍 London, England, United Kingdom· Full-time· Remote
✓ High-confidence listingCompany trend -10%
Quick readStrong listing-quality and freshness signals

🚀 About WRITER WRITER is where the world's leading enterprises orchestrate AI-powered work. Our vision is to expand human capacity through superintelligence. And we're proving it's possible – through powerful, trustworthy AI that unites IT and business teams together to unlock enterprise-wide transformation. With WRITER's end-to-end platform, hundreds of companies like Mars, Marriott, Uber, and Vanguard are building and deploying AI agents that are grounded in their company's data and fueled by WRITER's enterprise-grade LLMs. Valued at $1.9B and backed by industry-leading investors including Premji Invest, Radical Ventures, and ICONIQ Growth, WRITER is rapidly cementing its position as the leader in enterprise generative AI. Founded in 2020 with office hubs in San Francisco, New York City, Seattle, Austin, Chicago, and London, our team thinks big and moves fast, and we're looking for smart, hardworking builders and scalers to join us on our journey to create a better future of work with AI. 📐 About the role This is where security meets innovation at enterprise scale. As a security engineer, applications at WRITER, you'll be building the security foundations that protect the AI systems powering some of the world's most recognizable brands. You'll work at the intersection of application security, AI infrastructure, and developer enablement—partnering with engineering teams to embed security into every line of code while ensuring our platform remains both powerful and trustworthy. The opportunity is massive: you'll help define how enterprise AI applications are secured, from threat modeling our LLM architectures to building automated security controls that scale across our growing platform. This isn't about saying "no"—it's about finding creative ways to say "yes, and here's how we do it securely." You'll tackle challenges that most security engineers never encounter: securing AI agents, protecting training data pipelines, and designing controls for systems that didn

JavaScriptTypeScriptPythonJava
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📍 London, England, United Kingdom· Full-time· Remote
✓ High-confidence listingCompany trend -10%
Quick readStrong listing-quality and freshness signals

🚀 About WRITER WRITER is where the world's leading enterprises orchestrate AI-powered work. Our vision is to expand human capacity through superintelligence. And we're proving it's possible – through powerful, trustworthy AI that unites IT and business teams together to unlock enterprise-wide transformation. With WRITER's end-to-end platform, hundreds of companies like Mars, Marriott, Uber, and Vanguard are building and deploying AI agents that are grounded in their company's data and fueled by WRITER's enterprise-grade LLMs. Valued at $1.9B and backed by industry-leading investors including Premji Invest, Radical Ventures, and ICONIQ Growth, WRITER is rapidly cementing its position as the leader in enterprise generative AI. Founded in 2020 with office hubs in San Francisco, New York City, Seattle, Austin, Chicago, and London, our team thinks big and moves fast, and we're looking for smart, hardworking builders and scalers to join us on our journey to create a better future of work with AI. 📐 About the role Join WRITER's security team as a staff detection and response engineer and help protect the AI infrastructure that's transforming how the world works. You'll build sophisticated detection systems that identify attacks targeting our AI platform, training data, and model deployments while creating automated response capabilities that scale with our explosive growth. This isn't just traditional security work – you're defending cutting-edge AI/AGI systems against adversaries who are evolving their tactics as fast as AI itself advances. This role combines hands-on security engineering with strategic thinking to stay ahead of novel threats that don't exist in textbooks yet. You'll be the operational arm of our security function, translating threat intelligence into real-time detections, coordinating incident response across multiple teams, and hunting for sophisticated attacks across GPU clusters and distributed training environments. If you're excited by the challen

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