Senior Security Engineer

About WexlerWexler is at the forefront of developing an unparalleled AI system tailored for litigation. Collaborating with some of the largest law firms globally, we assist them in navigating their most intricate cases, identifying winning strategies, and distilling clarity from the often overwhelming array of documents and facts. Based in London, we are a rapidly expanding legal AI company, trusted by firms like Clifford Chance, HSFKramer, Goodwin, and Addleshaw Goddard to uncover critical insights that can significantly impact case outcomes.Supported by a $5.3M Seed funding from Pear VC, Seedcamp, The LegalTechFund, and several prominent industry angels, we are committed to building a comprehensive AI platform designed to manage, resolve, and preempt legal disputes for enterprise law firms and Fortune 500 companies. Our growth trajectory of 10x year-over-year and the continuous acquisition of prestigious firms speaks to our success. Our innovative system efficiently extracts objective, cross-referenced facts from millions of documents, empowering litigators to secure more victories while conserving invaluable time. This ensures that every client receives the exceptional representation they rightfully deserve.At Wexler, we understand that AI is revolutionizing the legal landscape, yet many existing tools tend to focus on contract law or serve as generalist copilots. We pride ourselves on being the leading generative AI platform specifically crafted for the intricacies of litigation, a fact underscored by our remarkable growth.About the RoleAs our inaugural dedicated security engineer, you will play a pivotal role in establishing and managing the bedrock of Wexler's security framework, encompassing infrastructure, product, and compliance. Your collaboration with engineering, operations, and leadership teams will be essential to not only enhance our security measures but also to provide tangible proof of our commitment to security for our clients.Responsibilities:Take charge of current security tools and introduce new solutions (e.g., endpoint protection, MDM, access controls), ensuring their effective configuration, maintenance, and scalability as the organization expands.Integrate secure-by-design practices throughout the development lifecycle, from secure coding and threat modeling to design reviews and CI/CD hardening.Monitor systems for any anomalies and proactively design detection and prevention mechanisms.Ensure that infrastructure and applications comply with accepted industry standards (e.g., OWASP Top 10, AWS Well-Architected Framework).Conduct and lead risk assessments, including evaluations of third-party vendors and internal processes.

Join us at tracebit, where we empower security teams to swiftly and accurately identify intrusions within their cloud environments. Our innovative product utilizes deceptive canaries—virtual tripwires designed to mislead potential attackers.This is an exhilarating moment to become a part of our founding team:We are supported by top-tier investors including Accel and Tapestry.Our growth trajectory is remarkable; we doubled our Annual Recurring Revenue (ARR) last quarter and have secured major clients like Riot Games, Synthesia, Docker, Coveo, and Snyk, along with several others who we can’t publicly disclose.As one of the most promising startups in the UK, we have received outstanding market feedback and are poised for explosive expansion.We are frequently featured in esteemed startup rankings...Creandum’s Euro Seed Top 50 List, Sifted’s 2025 London Startups To Watch, Notion’s Cloud Top 100, and more.Our research has recently played a crucial role in resolving a critical security vulnerability in Google’s Gemini CLI.Having started with just 2 employees 18 months ago, we have expanded to 18 and plan to triple our team in the coming year.We are addressing substantial challenges for discerning organizations. Our streamlined tech stack empowers us to process billions of events weekly while maintaining robust security.

Join Gradient Labs in revolutionizing customer experiences and operational efficiency in the financial services sector.Founded in 2023, Gradient Labs has rapidly evolved from an innovative concept to a dynamic team serving well-known clients. Our unique AI operations agent is the first of its kind tailored specifically for financial services, adept at addressing high-stakes customer inquiries with precision and safety. This all-encompassing agent provides businesses with the visibility and control needed for reliable outcomes across their operations.Our team comprises talented individuals from prestigious companies such as Monzo, Pleo, and Google. If you are eager to tackle complex challenges in AI and contribute to the future of customer operations and experience, we invite you to connect with us. Your Role and ImpactWe are in search of our inaugural Founding Platform & Security Engineer, a dedicated and skilled professional to join our expanding team. In this pivotal greenfield position, you will play a crucial role in designing and securing our advanced AI agent platform and its infrastructure from the ground up.As you report directly to the CTO, you will establish the technical vision for Platform & Security while working closely with AI, engineering, and product teams to effectively scale and deploy our platform across various cloud environments. This role offers an exciting opportunity to leverage your extensive security expertise, particularly within the AI domain, to create enterprise-grade security systems in a fast-paced and evolving landscape.Ownership of Scaling Deployments: Lead the charge on application, cloud, network, and AI agent scalability across our platform, driving the global deployment of our agent across multiple cloud environments.Architect & Implement Security Framework: Design and establish a robust security framework that encompasses customer-facing products, cloud infrastructure (AWS, Azure, or GCP), and enterprise integration points, safeguarding against both traditional and modern AI-enabled threats.Integrate Security within AI: Collaborate with our AI engineering teams to embed security best practices throughout model training, evaluation, and deployment processes, enabling innovation while maintaining safety and responsibility.Automation & Tooling: Enhance security operations through the integration of tools into CI/CD pipelines, ensuring efficiency and effectiveness.

Corgi is a licensed insurance carrier designed for tech startups, powered by AI. With $108M in funding and regulatory approval, Corgi is expanding into the UK and EU markets. The platform is built on Django, integrates Stripe for payments, and features AI-driven underwriting. Role overview Corgi is searching for a Founding Software Engineer based in London. This position calls for someone who brings ideas to life, taking projects from concept to live product. Candidates with a track record of side projects, shipped products, or anything that has gained real user engagement will stand out. This is more than a senior engineer role by title; it’s about building and launching real solutions. What you will do Independently build and deploy products from the ground up Work across the technology stack, handling new challenges as they arise Deliver results quickly, often within hours or days Contribute to a culture that values shipping and iterating frequently Participate in open and transparent decision-making Requirements Demonstrated experience developing and launching projects independently Comfort working across a broad technology stack Strong, experience-backed opinions with a willingness to consider better ideas Ambition and energy suited to a rapid startup pace Focus on delivering results rather than relying on job titles Work culture Decisions made quickly, even with incomplete information Frequent releases and continuous improvements Short review cycles with a focus on shipping and iterating Consistent performance expected beyond just launch periods Transparent, public-first communication style Healthy internal competition that encourages growth This is a hands-on build role. Consistent effort is expected; coasting is not an option. Behaviors that do not fit Engaging in workplace politics, gossip, or avoiding accountability Taking feedback personally instead of using it for improvement Introducing unnecessary bureaucracy rather than simplifying processes Failing to deliver after making commitments How to apply Send links to your GitHub, personal website, or live projects you have built and launched Resumes are not accepted Email: sergio@corgi.com If you cannot show shipped work, this role is not a fit Compensation and location Role based in London (on-site or hybrid) Salary range: £75,000 to £140,000, plus equity options Compensation depends on demonstrated ability to ship, not job title

Corgi provides insurance for technology startups, using AI to streamline underwriting and operations. With $108 million in funding and full regulatory approval as a licensed carrier, Corgi is expanding into the UK and EU. The platform uses Django, integrates Stripe for payments, and relies on AI-driven processes at every stage. Role overview This founding engineer position is based in London and focuses on building and shipping real products. Joining at an early stage, the role involves shaping both the product and company culture as Corgi grows in new markets. The work is hands-on, with a strong emphasis on delivering live solutions rather than just planning or design. Requirements Track record of independently building and launching projects with real user engagement and polished outcomes Comfort working at a daily pace, prioritizing progress over prolonged planning Ability to work across the technology stack and solve problems directly Strong opinions, balanced by openness to better solutions Humble attitude and genuine drive to build and improve How Corgi works Decisions are made quickly, without waiting for perfect answers Products and improvements are released regularly, not just quarterly Ship-and-iterate mindset keeps momentum high and avoids bureaucracy Consistent intensity during product pushes, with minimal slowdowns Decisions are made transparently High performers help raise the bar for the team This is not a passive or comfortable position. The role suits those who want to build and take ownership. Behaviors that lead to removal Engaging in office politics, avoiding responsibility, or gossiping Treating direct feedback as a personal attack Adding unnecessary complexity instead of improving efficiency Missing deadlines after making commitments How to apply Instead of a resume, send links to your work, such as: GitHub repositories Personal website Live projects Shipped applications Email applications to: sergio@corgi.com Candidates must have demonstrable projects to share. If not, this role is not a fit. Location This position is based in London. On-site or hybrid work options are available. Compensation Salary ranges from £75,000 to £140,000, plus equity. The range reflects a focus on real shipping ability over job titles.

Your RoleAs a Founding Engineer at Marloo in London, you will play a pivotal role in shaping the future of our product. Your responsibilities will include:End-to-End Full-Stack DevelopmentOwn and develop core product features, working seamlessly from backend infrastructure to engaging frontend experiences, prioritizing rapid delivery and continuous iteration.Architectural LeadershipEstablish sustainable technical patterns and make crucial architectural decisions that align with our growth trajectory. You will be the guiding authority on our codebase and influence our engineering culture significantly.Collaborative Product DevelopmentEngage directly with the founders to convert user feedback into innovative technical solutions. Your understanding of business needs and product development will be as essential as your technical skills.AI-Driven DevelopmentUtilize AI tools daily to enhance your development processes, from architecture to debugging. We expect you to be an adept user of the latest AI development technologies.

Corgi is a licensed insurance carrier focused on tech startups, using AI to simplify and speed up coverage. The company has raised $108M and is expanding across the UK and EU. The platform relies on Django, integrates Stripe for payments, and features AI-driven underwriting. Role overview This founding engineer role is based in London and centers on building and launching new products, often independently. Corgi values engineers who turn ideas into live products, rather than following detailed roadmaps. Evidence of shipped side projects, weekend builds, or products that have reached real users is highly regarded. Who succeeds here Track record of independently building and delivering real projects Comfortable working across the full technology stack Delivers results quickly, in hours or days Low-ego, motivated by results rather than titles Open to feedback and willing to adopt better ideas Thrives in a high-energy startup setting How we work Decisions are made quickly; perfection is not the goal Products and processes ship regularly, not just quarterly Iteration happens after shipping, not after long review cycles High intensity during launches, with a steady pace year-round Transparent decision-making; no closed-door policies Internal competition is encouraged to raise standards This is a hands-on role for builders who want to make things happen. Behaviors that don’t fit Office politics, gossip, or avoiding responsibility Taking direct feedback personally instead of constructively Adding unnecessary overhead instead of streamlining Missing deadlines after committing to them Application process Send links to your GitHub, personal website, live projects, or shipped products CVs are not accepted Email applications to: sergio@corgi.com Evidence of shipped work is required for consideration Location and compensation Role is based in London; on-site or hybrid arrangements available Base salary: £75,000–£140,000, plus equity Salary band reflects proven shipping ability, not job titles

Salary: £150,000 – £170,000Equity: 0.7% - 1.2%This position is in-person with flexible remote workdays.European visa sponsorship is available.About AuroraAurora is redefining the lifestyle operating system for top-performing individuals and organizations worldwide. Our clientele includes elite founders, executives, professional athletes, and families managing intricate and ongoing needs across travel, health, dining, and premium goods.Our platform is conversational, proactive, and accessible 24/7 globally, making it a vital tool for members who engage with it multiple times daily for crucial, time-sensitive decisions. The quality of our product, the soundness of our judgment, and the efficiency of our systems are instantly visible to our customers.The market for agentified premium lifestyle commerce exceeds $10 billion, with traditional concierge services often hampered by disjointed CRM systems and manual processes that lack scalability. Aurora integrates automation, AI agents, and expert human curators into a unified system, engineered for speed, precision, and impact.We have achieved remarkable early success:51% daily active users, 95% weekly active usersTransaction volume and member spending have surpassed industry benchmarks by 5x within the first three monthsBacked by Alex Macdonald, a leading figure in this domain, we have:Secured over $5 million in funding from seasoned operators and top-tier investorsDeveloped a product that boasts industry-leading engagement from paying membersAccumulated a substantial, proprietary dataset of user context (preferences, calendars, health signals) that fuels our proactive AI capabilitiesAs we scale our product and expand our member base, we are looking to grow our founding engineering team.Aurora operates from our offices in London, New York, and Los Angeles. Our engineering team primarily collaborates from our London office in Belgravia, with options for flexible remote work.

About TracerTracer is an innovative early-stage startup that specializes in developing autonomous AI agents for production data pipelines. Backed by seasoned investors and industry leaders, we believe that AI will revolutionize production systems, becoming a key player in enterprise software over the next decade. Our team is composed of highly skilled professionals focused on delivering impactful results. Role OverviewWe are seeking a Founding AI Engineer (Staff) to join our London team. In this pivotal role, you will be responsible for designing the core architecture and launching an AI agent that generates reliable root cause analyses (RCAs) and actionable suggestions for significant alerts. While human oversight remains essential for production decisions, you will empower the agent to handle the intricacies of data management. Our Technology StackPython with LangGraph for multi-agent alert investigationsRust for high-performance systemsClickHouse for scalable event and investigation historyAWS and Terraform for self-managing infrastructureNext.js and TypeScript for an engaging front-end experience Your ResponsibilitiesAs the core architect, you will transform alerts into comprehensive investigations and RCAs. Your key tasks will include:Designing and building the primary alert investigation and RCA pipeline using PythonCreating essential systems such as alert ingestion, context enrichment, hypothesis orchestration, and reportingMaking critical architectural decisions to ensure reliability and observability from the outsetCollaborating with founders to refine and expand high-value alert typesDeveloping customer-ready integrations across the pipeline

Join weekday-1 as a Founding Software Engineer and become a key player in shaping our innovative technology solutions. As part of a dynamic startup team, you will be responsible for designing, developing, and maintaining cutting-edge software applications that will drive our vision forward.We are looking for an enthusiastic and skilled engineer who thrives in a fast-paced environment and is eager to take on new challenges. Your contributions will directly impact our success, making this an exciting opportunity for those looking to make their mark in the tech industry.

Abound is changing how consumer lending works in the UK and beyond. By combining advanced AI with Open Banking data, the company looks at a person’s complete financial situation, not just a credit score, to make lending decisions that are fairer and more accurate. Since launch, Abound has issued over £1.3bn in loans, with a credit performance that outpaces industry averages. The company became profitable within 2.5 years and has backing from major investors, including Citi and Deutsche Bank. With over £2bn in funding, Abound is recognized as one of Europe’s fastest-growing fintechs. Role overview This Senior Security Engineer position is based in London and sits within the Platform team. The role blends DevSecOps responsibilities, serving as a bridge between product engineering and Corporate IT. As a hands-on contributor, the Senior Security Engineer critically reviews security architecture across both production and internal IT environments. During the first 6 to 12 months, the focus will be on designing and implementing next-generation cloud security architecture in AWS and GCP. The role also involves building and maturing internal SOC capabilities, particularly around detection and response. What you will do Manage Microsoft Sentinel to strengthen SIEM/SOAR capabilities Automate RBAC for identity and access management across AWS, Microsoft Entra, and internal systems Embed security controls into GitLab CI/CD pipelines, including scanning, infrastructure-as-code reviews, and automated policy enforcement Support a shift-left approach by integrating security throughout the software development lifecycle Technology stack Cloud & Compute: AWS, ECS Fargate, Aurora, Lambda, GCP Data Lake: S3, DMS, Glue Security & Identity: Microsoft Defender (XDR), Microsoft Sentinel (SIEM/SOAR), Defender for Cloud (CSPM), Microsoft 365, Entra, Intune Cloud Security Tooling: GuardDuty, Security Hub, Inspector, Security Command Center Code & Infrastructure: Terraform, GitLab CI/CD

airapps is hiring a Security Engineer to help safeguard digital assets and infrastructure in the London Metropolitan Area. This role centers on identifying weaknesses, managing security risks, and ensuring strong security measures are in place. Key responsibilities Identify vulnerabilities throughout information systems Reduce and address security risks as they arise Implement and maintain effective security protocols Support efforts to comply with relevant industry standards Help strengthen the company’s overall security posture Location This position is based in the London Metropolitan Area.

ABOUT AvolutionJoin Avolution, a prestigious global leader in Enterprise Architecture Software with over 20 years of experience. Our established presence spans across London, Sydney, Northern Virginia, and Singapore, and we are recognized in the Gartner Magic Quadrant as an industry frontrunner. Become part of our intelligent, friendly team, where your skills and initiative will drive our growth while enjoying a culture rated as collegial, collaborative, flexible, and supportive by our employees.Key ResponsibilitiesCloud & Infrastructure SecurityDesign, manage, and enhance security configurations across Azure and AWS environments, ensuring seamless integration with Office 365.Implement and enforce industry best practices for identity and access management (IAM) in Azure AD (Entra ID) and AWS IAM.Monitor cloud workloads for vulnerabilities, misconfigurations, and threats utilizing tools such as Microsoft Defender.Collaborate with DevOps/Engineering teams to embed security controls into CI/CD pipelines, advocating for DevSecOps principles.Conduct thorough security assessments, including aiding in penetration testing and risk evaluations to identify and mitigate potential vulnerabilities.Endpoint & Identity SecurityEnhance device posture, compliance, and management utilizing Microsoft Intune and Defender for Endpoint.Develop and maintain solid conditional access, multi-factor authentication (MFA), and endpoint protection policies.Oversee secure identity lifecycle processes, enforcing least-privilege access and zero-trust principles.Security OperationsRespond promptly to security alerts, incidents, and vulnerabilities with thorough investigations and remediation actions.Perform regular risk assessments, security reviews, and internal audits.Manage and optimize security tools, including SIEM, EDR, vulnerability scanners, and the Microsoft Defender suite.Lead incident response efforts and coordinate with cross-functional teams.Compliance & GovernanceSupport ISO 27001:2022 recertification and ongoing compliance activities, including internal audits.Prepare for and assist in obtaining additional compliance certifications (e.g., SOC 2, GDPR) to facilitate company growth.Develop, maintain, and enhance security policies, procedures, and technical documentation.Track, report on, and address audit findings or compliance gaps.Collaboration & CulturePartner with globally distributed teams across EMEA, AMER, and APAC regions.Educate internal teams on security best practices and cultivate a security-first culture through training and awareness initiatives.

Role Overview Aircall is looking for a Security Engineer focused on Product Security to help protect our products and platform. This role is based in our London office. What You Will Do Work with teams across engineering, product, and other functions to spot vulnerabilities and address them early in the development process. Implement security measures that fit our product development lifecycle. Lead security initiatives that strengthen customer trust and protect sensitive data. Support efforts to keep our security standards high as our platform evolves. Impact This role directly shapes the security of Aircall’s products and the safety of customer data. The work supports our commitment to strong security practices and helps maintain trust with our users.

Join Us in Shaping the Future of Cyber Security.At Quantexa, we believe in the power of innovation and continuous improvement. Our mission is to forge meaningful relationships with our clients and drive impactful change across various industries. With a diverse workforce comprising over 50 nationalities and 20 languages spoken, we foster an inclusive environment where every voice matters. Here, you will find the autonomy and support needed to craft a career that aligns with your aspirations.The Role.We are seeking a proactive and technically skilled Cyber Security Engineer to join our Security Operations team. In this hands-on role, you will be instrumental in safeguarding Quantexa's digital assets. Your responsibilities will include the operational management, optimization, and monitoring of essential security platforms, focusing on Zscaler, cloud monitoring via Wiz, and endpoint detection and response through CrowdStrike.Collaborating closely with the broader Security Operations team, you will ensure that security alerts, findings, and detections are efficiently triaged, validated, documented, and remediated. Your contributions will directly enhance Quantexa's security posture by minimizing risk, bolstering detection capabilities, and ensuring timely responses to security incidents.This position is ideal for a curious and detail-oriented professional who thrives on working with cutting-edge security tools, embraces disciplined execution, and seeks opportunities for ongoing improvement.Your Responsibilities.Wiz (Cloud Security Posture Management)Daily monitoring and triaging of Wiz findings, validating alerts and assessing operational impact.Engaging in tuning and threat hunting within Wiz and other security tools.Identifying misconfigurations, excessive permissions, and exposed assets while escalating issues as necessary.Tracking remediation progress with engineering teams and ensuring the resolution of high-priority issues.Zscaler (Web Security Tunnel 2.0)Reviewing and triaging Zscaler alerts and policy violations according to documented response procedures.Investigating suspicious traffic, access attempts, and user activity to determine legitimacy.

About the Position Jane Street is seeking a skilled Identity Security Engineer with expertise in engineering hybrid Windows platforms to become a vital member of our expanding team. Our IT Security team is committed to safeguarding access to Jane Street's IT systems. In this role, you will be instrumental in enhancing the organization's security posture through a blend of hands-on technical work and collaborative efforts with cross-functional engineering teams to initiate transformative security projects. Key Responsibilities: Serve as a technical security authority, offering insights on EntraID, M365, Azure tools, and security best practices. Lead the implementation and validation of robust security controls to minimize attack pathways between on-premises and external platforms. Identify security vulnerabilities and recommend operational improvements to meet our security standards. Provide technical guidance and influence cross-functional technology teams to facilitate cloud adoption. We are looking for an individual ready to make an immediate impact, capable of prioritizing work in a fast-paced environment. This position is more than just execution; we will rely on your judgment and quick thinking to guide our remediation and mitigation strategies for our Windows infrastructure. Your decisions will have far-reaching implications across the firm. About You: Possess a solid understanding of Microsoft security policies and configurations across Microsoft cloud services (SaaS/PaaS), IAM, and Privilege Access Management. Exhibit a strong grasp of industry-standard SSO technologies and authentication protocols (OpenID Connect, SAML, OAuth, Kerberos, LDAP, etc.). Have experience designing, implementing, and supporting Microsoft security infrastructure in live environments. Provide security recommendations regarding certificate policies, templates, and key sizes to uphold secure cryptographic standards. Manage and secure Azure resources utilizing a code-driven methodology. Be eager to develop scalable and repeatable security practices through automation, including certificate enrollment and renewal processes. Fluent in English. If you are a recruiting agency interested in partnering with us, please reach out to agency-partnerships@janestreet.com.

Join our dynamic team at Lendable as a Cyber Security Engineer, where you will play a pivotal role in safeguarding our digital assets and ensuring the integrity of our systems. In this position, you will be responsible for the design, implementation, and maintenance of security protocols across our network and applications. You will work closely with cross-functional teams to identify vulnerabilities and develop strategies to mitigate risks.

Role overview Granola is searching for a Founding Legal Counsel based in London. This position plays a central role within the founding team, responsible for building the company’s legal framework from the earliest stages. The scope is broad, covering everything from regulatory compliance to the protection of intellectual property. What you will do Provide legal guidance across all areas of the business as Granola grows Monitor and ensure compliance with applicable laws and regulations Protect the company’s intellectual property assets Support the team in navigating complex legal issues as they come up Requirements This role calls for a legal professional ready to take ownership of legal operations in a startup environment. Experience in compliance and intellectual property will be important as Granola builds its foundation.

Why Join Deliveroo?At Deliveroo, our mission is to revolutionize how people shop and dine by seamlessly connecting consumers, restaurants, shops, and delivery riders. We strive to make food and product accessibility more convenient and enjoyable, empowering individuals to purchase what they want, when and where they desire.As a forward-thinking, technology-driven organization, we are leading the charge in one of the fastest-growing industries globally. Our small team is making a significant impact as we tackle some of the most fascinating challenges. We prioritize speed, autonomy, and innovative ideas, continuously seeking fresh perspectives.About the RoleIn the role of Senior Security Engineer, you will spearhead the development and implementation of security measures that safeguard our internal networks, workforce identities, endpoints, and corporate systems. Collaborating with security teams across the US, EU, and APAC, you will aim to minimize risk and enhance our security controls.Operating with significant independence, you will define the technical strategy, make architectural decisions, and oversee the execution of complex security projects from start to finish. Your focus will be on balancing risk mitigation with user experience, ensuring that security measures are effective without hindering employee productivity.This position emphasizes Identity and Access Management (IAM), Endpoint Security (EDR), Network Security, logging and detection engineering, and secure SaaS enablement. You will collaborate closely with IT, Legal, Privacy, Engineering, and business stakeholders to ensure that security is integrated as a fundamental practice across the organization.Our security protocols are aligned with recognized frameworks such as the CIS Critical Security Controls and the NIST Cybersecurity Framework (CSF).