Application Security Engineer Jobs

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

Fin is the AI Customer Agent company on a mission to help businesses provide perfect customer experiences. Our AI Agent Fin is the highest-performing AI Customer Agent on the market today, enabling businesses to deliver impeccable, always-on customer support across the customer journey – from service, to sales, to ecommerce. Powered by our own AI models, Fin resolves complex customer issues end-to-end across every channel, with minimal set-up and integration. Fin can also be combined with our natively integrated Intercom help desk for one single system that is designed to meet the needs of modern day support teams. Founded in 2011, Fin became one of the fastest growing companies and remains one of the largest private software companies in the world with nearly 30,000 global businesses using our products to transform their customer support. Driven by our core values, we push boundaries, build with speed and intensity, and relentlessly deliver incredible value to our customers. What's the opportunity? Fin is transforming customer service through AI, helping businesses deliver fast, accurate, and reliable support at scale. Trust is foundational to that mission. Fin's Security Engineering team is unlike most security teams. We own and operate critical security services, build customer-facing security features, and partner with engineering teams to make secure development the default. We're engineers first; designing, building, and operating systems that protect Fin and its customers. The team owns and operates tier-zero services including authentication, SAML/SSO, teammate activity logs, malicious URL scanning, and other critical trust and security capabilities. The mission of the team is to help Fin build and operate trusted AI-powered customer service experiences by making security a natural part of how products are designed, developed, and delivered. As Fin continues to expand its capabilities and adoption, you'll help shape how security evolves alongside some of the

Fin is the AI Customer Agent company on a mission to help businesses provide perfect customer experiences. Our AI Agent Fin is the highest-performing AI Customer Agent on the market today, enabling businesses to deliver impeccable, always-on customer support across the customer journey – from service, to sales, to ecommerce. Powered by our own AI models, Fin resolves complex customer issues end-to-end across every channel, with minimal set-up and integration. Fin can also be combined with our natively integrated Intercom help desk for one single system that is designed to meet the needs of modern day support teams. Founded in 2011, Fin became one of the fastest growing companies and remains one of the largest private software companies in the world with nearly 30,000 global businesses using our products to transform their customer support. Driven by our core values, we push boundaries, build with speed and intensity, and relentlessly deliver incredible value to our customers. What's the opportunity? Fin is transforming customer service through AI, helping businesses deliver fast, accurate, and reliable support at scale. Trust is foundational to that mission. Fin's Security Engineering team is unlike most security teams. We own and operate critical security services, build customer-facing security features, and partner with engineering teams to make secure development the default. We're engineers first; designing, building, and operating systems that protect Fin and its customers. The team owns and operates tier-zero services including authentication, SAML/SSO, teammate activity logs, malicious URL scanning, and other critical trust and security capabilities. The mission of the team is to help Fin build and operate trusted AI-powered customer service experiences by making security a natural part of how products are designed, developed, and delivered. As Fin continues to expand its capabilities and adoption, you'll help shape how security evolves alongside some of the

The Security team is responsible for protecting Asana’s employees, users, and customers. We are a team of security engineers and risk and compliance practitioners who build innovative safeguards to ensure that our data is protected against threats and that we comply with legal, regulatory, and customer requirements. We collaborate closely with teams across the organization to foster a culture of security throughout our product and operations. We’re looking for an Application Security Engineer to join our Security team in Warsaw. You’ll be a foundational member of the security presence in a key engineering hub, partnering directly with IT, infrastructure, and product teams to ensure we design and ship secure software. You will be instrumental in scaling our security practices by conducting security design reviews, threat modeling, and vulnerability assessments across our products and internal applications, eliminating entire classes of vulnerabilities, and championing a security-first mindset. This role is based in our Warsaw office with an office-centric hybrid schedule. The standard in-office days are Monday, Tuesday, and Thursday. Most Asanas have the option to work from home on Wednesdays. Working from home on Fridays depends on the type of work you do, and your recruiter can share more about the in-office requirements. We offer a Contract of Employment (UoP) for our employees in Poland. What you’ll achieve ● Conduct security architecture reviews and threat modeling for new features and services across our product and internal applications, identifying risks early and influencing secure design decisions. ● Perform vulnerability assessments of software and systems, using a range of assessment methodologies to surface and prioritize security weaknesses across our product surface. ● Triage, investigate, and drive remediation of vulnerabilities from our bug bounty program and automated s

As a Staff Application Security Engineer at Datadog, you'll set technical direction for how we approach application security at scale. You'll define the frameworks, methodologies, and architectural patterns that engineering teams across Datadog adopt and apply independently. You're the person others come to when they don't know how to make something secure, and you reliably have an answer. You'll be a point of contact for our most complex security programs, often spanning multiple teams and multiple quarters. The role requires both depth (going very deep on specific problems when needed) and breadth (recognizing patterns across systems and drawing connections that others miss). Partnering closely with teams inside and outside the security org is key to success. You'll help shape the AppSec roadmap and make the case for where investment should go. We use our own platform. Logs, Dashboards, Service Catalog, and APM aren't just things we sell: they're tools the AppSec team uses to build security services, measure adoption of secure defaults, and communicate risk across the organization. AI is also part of the picture. Engineering at Datadog increasingly uses agentic tooling throughout the development lifecycle, and many of the products we ship to customers now include AI-powered features. Both create new attack surfaces, and defining our strategy for addressing them is part of this role. If using Datadog to observe Datadog's own security posture, building impactful tooling, and shaping how we secure AI-powered systems sounds like the right kind of problem, this role is worth a close look. What You’ll Do: Define and drive security standards and secure-by-default solutions, serving as the Application Security subject matter expert. Build security tooling and automation that scales security practices across engineering teams, and implement robust security observability to support our threat detection team with meaningful, actionable security signals. Lead threat mod

🚀 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 staff 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 tha

Discord has a highly engaged community of millions of daily active users who use the platform for many different reasons, but there’s one thing that nearly everyone does: play video games. Discord plays a uniquely important role in the future of gaming, and we are focused on making it easier and more fun for people to hang out before, during, and after playing games. Discord empowers people to create spaces where they can find a sense of belonging in their lives. Millions of people trust Discord to keep their communications secure, private, and out of the hands of evildoers, so security and privacy are necessary to Discord's success. We are looking for a Senior Software Engineer to join our Application Security team and protect Discord’s users where it matters most, their accounts. If you are an engineer with a wealth of experience making the secure way the easy way, a deep sense of curiosity, and an endless desire to improve Discord, read on! What you'll do Join an engineering team designing and implementing full-stack, user-facing security solutions that protect hundreds of millions of Discord users. Lead full-stack work to strengthen session security and authentication for Discord’s users. Improve, operate, and maintain security-critical authentication services, owning their correctness and security. Partner with Product teams to drive adoption of stronger authentication and to ship user-facing account security tools. Identify and design solutions for emerging threats to user account security. Research and implement new security capabilities for the Discord platform, staying current on the authentication and session security landscape. Build security controls and tools that emphasize self-service, automation, and performance to help identify and mitigate account security flaws. Who you are You have 5+ years of experience securing production applications. You have 3+ years of experience programming in at least one general-purpose programming language (e.g., Python

🚀 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

🚀 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

🚀 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

About Sentry Software runs the world and the pace is faster than ever. Sentry helps developers fix errors and performance issues before users notice, so teams can spend less time firefighting and more time building. Trusted by 200,000+ organizations, Sentry is today’s application monitoring standard and our team is building its AI-native future. About The Role The Security Team is responsible for securing all things Sentry: our customers, our code, and everything in between. We are a small but growing team with broad scope, high trust, and the autonomy to tackle hard security problems with creativity and an engineering mindset. We work at a company with a strong developer culture, building a product that millions of developers genuinely love and rely on. That context shapes everything about how we operate. As a Security Engineer on this team, you'll work across application and platform security domains. You'll contribute to the practices that keep Sentry secure as we grow: security reviews, threat modeling, vulnerability management, and embedding secure coding practices into an engineering organization that cares about doing things right. You'll partner closely with product and engineering teams to influence how features are designed and built from the start. You will work as a technical collaborator who helps make the secure path the obvious one. As Sentry expands our agentic product capabilities and development practices, you'll also find yourself at the frontier of a new set of security challenges. In this role, you will Support and help mature Sentry's security review program. From secure code review, to architecture review, and threat modeling. You'll help build the processes, tooling, and culture which make security a natural part of how we ship and operate. Contribute to mature vulnerability management practices. Intake, triage, prioritization, remediation tracking, and support of our bug bounty and responsible disclosure program. Advocate for secure-by-desig

About Sentry Software runs the world and the pace is faster than ever. Sentry helps developers fix errors and performance issues before users notice, so teams can spend less time firefighting and more time building. Trusted by 200,000+ organizations, Sentry is today’s application monitoring standard and our team is building its AI-native future. About The Role The Security Team is responsible for securing all things Sentry: our customers, our code, and everything in between. We are a small but growing team with broad scope, high trust, and the autonomy to tackle hard security problems with creativity and an engineering mindset. We work at a company with a strong developer culture, building a product that millions of developers genuinely love and rely on. That context shapes everything about how we operate. As a Security Engineer on this team, you'll work across application and platform security domains. You'll contribute to the practices that keep Sentry secure as we grow: security reviews, threat modeling, vulnerability management, and embedding secure coding practices into an engineering organization that cares about doing things right. You'll partner closely with product and engineering teams to influence how features are designed and built from the start. You will work as a technical collaborator who helps make the secure path the obvious one. As Sentry expands our agentic product capabilities and development practices, you'll also find yourself at the frontier of a new set of security challenges. In this role, you will Support and help mature Sentry's security review program. From secure code review, to architecture review, and threat modeling. You'll help build the processes, tooling, and culture which make security a natural part of how we ship and operate. Contribute to mature vulnerability management practices. Intake, triage, prioritization, remediation tracking, and support of our bug bounty and responsible disclosure program. Advocate for secure-by-desig

🚀 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

🚀 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

Join us in building the future of finance. Our mission is to democratize finance for all. An estimated $124 trillion of assets will be inherited by younger generations in the next two decades. The largest transfer of wealth in human history. If you’re ready to be at the epicenter of this historic cultural and financial shift, keep reading. About the team + role We are building an elite team, applying frontier technologies to the world’s biggest financial problems. We’re looking for bold thinkers. Sharp problem-solvers. Builders who are wired to make an impact. Robinhood isn’t a place for complacency, it’s where ambitious people do the best work of their careers. We’re a high-performing, fast-moving team with ethics at the center of everything we do. Expectations are high, and so are the rewards. The Proactive Security team builds and operates systems that help engineers identify and resolve security risks earlier in the software development lifecycle. The team creates practical safeguards, including shared libraries, frameworks, and automated checks that make secure development easier to adopt. You’ll work closely with product and engineering teams to reduce risk at scale while supporting efficient product development. The team values clear communication, sound judgment, and security practices that are useful for engineers building production systems. This is a meaningful opportunity to help strengthen application security across Robinhood! As a Security Engineer on the Application Security Team, you will help design and implement systems that embed security into development practices across Robinhood. You will review system designs, contribute to threat models, and guide secure implementation for product and platform teams. You will also build and improve security solutions and guardrails that give engineers clear patterns for developing secure services. You will utilize frontier AI models and tooling to help define the future of security at Robinhood. This r