Application Security Engineer

Okta

Secure Every Identity, from AI to Human Identity is the key to unlocking the potential of AI. Okta secures AI by building the trusted, neutral infrastructure that enables organizations to safely embrace this new era. This work requires a relentless drive to solve complex challenges with real-world stakes. We are looking for builders and owners who operate with speed and urgency and execute with excellence. This is an opportunity to do career-defining work. We're all in on this mission. If you are too, let's talk. As a Staff Product Security Engineer, you will play a critical role in safeguarding Okta’s products by conducting comprehensive security reviews, guiding engineering teams in secure development practices, and handling externally reported vulnerabilities. You will engage in code reviews, penetration testing, and architectural security assessments to ensure the security of Okta’s platforms and features. This role is not suited for individuals who rely solely on automated vulnerability scanning. Instead, you must possess a deep technical understanding of web applications, backend services, penetration testing methodologies, and secure design principles. A successful candidate will have expertise in authentication protocols (SAML, OAuth, OIDC), threat modeling, and a strong desire to automate security processes by building tools that proactively identify vulnerabilities. You will also be responsible for communicating risks, impact, and remediation strategies to developers, leadership, and external audiences through documentation, presentations, and external publications. The ideal candidate will also demonstrate a deep technical background in assessing AI-integrated software architectures and securing Large Language Models (LLMs) against emerging threats and modern vulnerability classes. The ideal candidate will have an attacker mindset—the ability to think critically, creatively, and like an adversary when solving security challenges. We actively support public disclosure of research and findings through white papers, blog posts, and conference presentations. Job Duties and Responsibilities: * Conduct security reviews, including design reviews, threat modeling, and penetration testing of new features and major changes. * Perform manual secure code reviews across multiple programming languages. * Identify and mitigate security vulnerabilities, providing clear guidance to engineering teams. * Lead product security incidents, assess risks, and drive remediation efforts. * Develop security tools and automation to improve vulnerability detection and assessment. * Mentor junior engineers and provide guidance to non-security staff on secure development practices. * Represent Okta externally through security research, conference talks, and publications. Required Knowledge, Skills, and Abilities: * Expertise in identifying OWASP Top 10 / CWE Top 25 vulnerabilities through manual code review. * Strong experience in penetration testing and secure development practices. * Deep technical background in assessing Large Language Models (LLMs) and securing AI-integrated software architectures. * Proficiency in multiple programming languages (e.g., Java, Go, Python, C/C++). * Deep understanding of authentication & authorization protocols (OIDC, SAML, OAuth). * Strong communication skills to explain risks and remediation to developers and leadership. * Ability to automate security testing using LLMs and scripting (Python, Bash, etc.). * Experience leading security incidents and risk assessments.  Desired Skills and Abilities: * Experience in mobile (iOS/Android) and desktop (Windows/macOS) security testing. * Familiarity with SAST, DAST, SCA, and fuzzing tools. * Strong cryptographic knowledge and secure implementation practices. * Experience analyzing network protocols and traffic security. * Ability to develop proof-of-concept exploits to demonstrate vulnerabilities. #LI-Remote #LI-AR P25283_3463317 Below is the annual salary range for candidates located in Spain. Your actual salary will depend on factors such as your skills, qualifications, and experience. In addition, Okta offers equity (where applicable), bonus, and comprehensive healthcare coverage and financial benefits including paid time off and parental leave in accordance with our applicable plans and policies. To learn more about our Total Rewards program, please visit: https://rewards.okta.com/esp. The annual base salary range for this position for candidates located in Spain is between: €74.000—€101.000 EUR The Okta Experience * Supporting Your Well-Being  * Driving Social Impact  * Developing Talent and Fostering Connection + Community We are intentional about connection. Our global community, spanning over 20 offices worldwide, is united by a drive to innovate. Your journey begins with an immersive, in-person onboarding experience designed to accelerate your impact and connect you to our mission and team from day one. Okta is an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, ancestry, marital status, age, physical or mental disability, or status as a protected veteran. We also consider for employment qualified applicants with arrest and convictions records, consistent with applicable laws. If reasonable accommodation is needed to complete any part of the job application, interview process, or onboarding please use this Form to request an accommodation. Notice for New York City Applicants & Employees: Okta may use Automated Employment Decision Tools (AEDT), as defined by New York City Local Law 144, that use artificial intelligence, machine learning, or other automated processes to assist in our recruitment and hiring process. In accordance with NYC Local Law 144, if you are an applicant or employee residing in New York City, please click here to view our full NYC AEDT Notice.

Monzo

🚀 We’re on a mission to make money work for everyone. We’re waving goodbye to the complicated and confusing ways of traditional banking. After starting as a prepaid card, our product offering has grown a lot in the last 10 years in the UK. As well as personal and business bank accounts, we offer joint accounts, accounts for 16-17 year olds, a free kids account and credit cards in the UK, with more exciting things to come beyond. Our UK customers can also save, invest and combine their pensions with us.  With our hot coral cards and get-paid-early feature, combined with financial education on social media and our award winning customer service, we have a long history of creating magical moments for our customers! We’re not about selling products - we want to solve problems and change lives through Monzo ❤️ ----------------------------------------------------------------------------------------------------------------------------------   📍Barcelona, Spain | 💰 Base salary for this role is depending on experience + benefits | Hybrid model: 3 days a week in the office About our Engineering Teams: We have over 400 engineers across Monzo who design and build our in-house banking platform. We have big ambitions for the future, and technology plays a big role in creating a bank our customers want, so engineers at Monzo collaborate across disciplines to solve interesting challenges throughout the company. These range from the products our customers use everyday to underlying infrastructure, security, payments and finance, customer operations, financial crime, and data, to name just a few areas. As a bank, there is scope for impact across a huge number of opportunities. We contribute to open source software as much as possible. Our blog is a good place to learn even more about what we do! What you’ll be working on:  We rely heavily on the following tools and technologies: * Go to write our application code (there’s an excellent interactive Go tutorial here) * Cassandra for most persistent data storage * Kafka for our asynchronous message queue * Envoy Proxy for RPC * Kubernetes and Docker to schedule and run our services  * AWS for most of our infrastructure * React for internal web dashboards * We also have two physical datacenter sites with actual cables to connect to various third parties Your day-to-day    This role is all about collaborating across disciplines to test hypotheses and make a difference to customers. As a product backend engineer you’ll work in a squad alongside product managers, marketers, user researchers, designers, mobile engineers, web engineers, data analysts, business analysts, writers and more!  Together you’ll build and support a particular part of Monzo. Our product squads belong to our wider collectives (a word we use to describe self-governing business units of ~100 people). They are; Money, Borrowing, Fincrime, Customer Operations, Platform, Personal Banking & Business Banking. They’re all looking for additional Backend Engineers right now, we do a standard interview process across all our collectives and at the end we will find the best match for you based on your skills, experience, preferences and aligning with the business need!  Our backend engineers have a variety of different backgrounds. As long as you enjoy learning new things, we’d love to talk to you. We do not ask for formal qualifications or degree requirements for any of our engineering roles. You should apply if: * you have strong experience working on the backend of a technology product * you want to be involved in building a product that you (and the people you know) use every day * you have a product mindset: you care about customer outcomes and you want to make data-informed decisions * you’re comfortable working in a team that deals with ambiguity * you’re interested in distributed systems and writing resilient software * you have some experience with strongly-typed languages (Go, Java, C, Scala etc.). * you think you’d enjoy the kind of work we’re doing We're on the look out for L60 Engineers at the moment, you can read more in our Engineering Progression Framework we are also hiring on L40 & L50, our interview process will determine your levelling.  The Interview Process: Our interview process involves three main stages:  1. Initial Call  2. Take home task or pair coding exercise  3. Final interview including a system design and a behavioural interview  One of our engineers has written a detailed blog on their experience through this process, for extra details, hints and tips please see here. What’s in it for you: 💰Base salary range for this role is depending on experience + equity + stock options & benefits  📍Barcelona, Spain ⏰ We offer flexible working hours and trust you to work enough hours to do your job well, at times that suit you and your team. 📚Learning budget of €1,200 a year for books, training courses and conferences #LI-JS1 ---------------------------------------------------------------------------------------------------------------------------------- Equal opportunities for everyone Diversity and inclusion are a priority for us and we’re making sure we have lots of support for all of our people to grow at Monzo. At Monzo, we’re embracing diversity by fostering an inclusive environment for all people to do the best work of their lives with us. This is integral to our mission of making money work for everyone. You can read more in our blog, 2026 Diversity and Inclusion Report and 2025 Gender Pay Gap Report. We’re an equal opportunity employer. All applicants will be considered for employment without attention to age, ethnicity, religion, sex, sexual orientation, gender identity, family or parental status, national origin, or veteran, neurodiversity or disability status. If you have a preferred name, please use it to apply. We don't need full or birth names at application stage 😊

Monzo

🚀 We’re on a mission to make money work for everyone. We’re waving goodbye to the complicated and confusing ways of traditional banking. After starting as a prepaid card, our product offering has grown a lot in the last 10 years in the UK. As well as personal and business bank accounts, we offer joint accounts, accounts for 16-17 year olds, a free kids account and credit cards in the UK, with more exciting things to come beyond. Our UK customers can also save, invest and combine their pensions with us.  With our hot coral cards and get-paid-early feature, combined with financial education on social media and our award winning customer service, we have a long history of creating magical moments for our customers! We’re not about selling products - we want to solve problems and change lives through Monzo ❤️ ----------------------------------------------------------------------------------------------------------------------------------   📍Barcelona, Spain | 💰 Base salary for this role is depending on experience + Incentive Awards tied to your performance  + benefits  Hybrid model: 3 days a week in the office About our Engineering Teams: We have over 400 engineers across Monzo who design and build our in-house banking platform. We have big ambitions for the future, and technology plays a big role in creating a bank our customers want, so engineers at Monzo collaborate across disciplines to solve interesting challenges throughout the company. These range from the products our customers use everyday to underlying infrastructure, security, payments and finance, customer operations, financial crime, and data, to name just a few areas. As a bank, there is scope for impact across a huge number of opportunities. We contribute to open source software as much as possible. Our blog is a good place to learn even more about what we do! Your day-to-day    This role is all about collaborating with your team to make a difference to your customers. As a backend engineer you’ll work in a squad alongside other disciplines like product managers, marketers, user researchers, designers, mobile engineers, web engineers, data analysts, business analysts, writers and more!  Together you’ll build and support a particular part of Monzo. Our squads belong to our wider collectives (a word we use to describe self-governing business units of ~100 people). They are; Core Banking, Business Banking, Wealth, Borrowing, Growth, Payments, Platform, Fincrime, Security & Expansion. They’re all looking for additional Backend Engineers right now, we do a standard interview process across all our collectives and at the end we will find the best match for you based on your skills, experience, preferences and aligning with the business need!  Our backend engineers have a variety of different backgrounds. As long as you enjoy learning new things, we’d love to talk to you. We do not ask for formal qualifications or degree requirements for any of our engineering roles. You should apply if: * you have strong experience working on the backend of a technology product * you want to be involved in building a product that you (and the people you know) use every day * you have a product mindset: you care about customer outcomes and you want to make data-informed decisions * you’re comfortable working in a team that deals with ambiguity * you’re interested in distributed systems and writing resilient software * you have some experience with strongly-typed languages (Go, Java, C, Scala etc.). * you think you’d enjoy the kind of work we’re doing We're on the look out for L50 Engineers at the moment, you can read more in our Engineering Progression Framework - we will interview you across the whole frame work, so if you are not sure what level you are aiming for please chat to your recruiters!  Not ticking every box? That’s totally okay! Studies show that women and people of colour might hesitate to apply unless they meet every single requirement. At Monzo, we’re dedicated to creating a diverse and welcoming team. If you’re passionate about this role and keen to learn and grow with us, we encourage you to apply— even if you don’t have everything thats listed just yet. Drop us your application, we’d love to hear from you! What you’ll be working on:  We hire very technically agnostic so whilst we use the below technologies we do not expect prior knowledge, you will be fully supported in our organised onboarding to get up to speed in the below:  * Go to write our application code (there’s an excellent interactive Go tutorial here) * Cassandra for most persistent data storage * Kafka for our asynchronous message queue * Kubernetes and Docker to schedule and run our services  * Envoy Proxy for RPC * AWS for most of our production infrastructure and GCP for most of our data infrastructure * React for our public web apps and internal tools * We also have physical datacenters with actual cables to connect to various third parties The Interview Process: Our interview process involves three main stages:  1. Initial Call  2. Take home task or pair coding exercise  3. Final interview: including a system design and a behavioural interview  Our average process takes around 4 weeks but we will always work around your availability.  One of our engineers has written a detailed blog on their experience through this process, for extra details, hints and tips please see here. What’s in it for you: 💰 Base salary for this role is depending on experience + Incentive Awards tied to your performance  + benefits  📍Barcelona, Spain ⏰ We offer flexible working hours and trust you to work enough hours to do your job well, at times that suit you and your team. 📚Learning budget of €1,200 a year for books, training courses and conferences   #LI-JS1 ---------------------------------------------------------------------------------------------------------------------------------- Equal opportunities for everyone Diversity and inclusion are a priority for us and we’re making sure we have lots of support for all of our people to grow at Monzo. At Monzo, we’re embracing diversity by fostering an inclusive environment for all people to do the best work of their lives with us. This is integral to our mission of making money work for everyone. You can read more in our blog, 2026 Diversity and Inclusion Report and 2025 Gender Pay Gap Report. We’re an equal opportunity employer. All applicants will be considered for employment without attention to age, ethnicity, religion, sex, sexual orientation, gender identity, family or parental status, national origin, or veteran, neurodiversity or disability status. If you have a preferred name, please use it to apply. We don't need full or birth names at application stage 😊