Senior Application Security Engineer

Please note that we are unable to consider applications from candidates based in France, Italy, or Germany for this role. Money is moving onto the internet, and the shift has a name: Open Money. This is money that is open, portable, agentic, and owned by you. MetaMask spent the last ten years building it; with 100M+ downloads, users in ~190 countries, and trillions in cumulative transaction volume, it’s the most trusted self-custodial financial platform on the internet. Now we’re building the operating system for your money: one place to hold, move, grow, and use anything you own. Join a remote-first, global team rebuilding how money works: a problem that touches everyone, every day. About MetaMask We’re building for a future where the internet and world economy empowers people through interactions based on consent, privacy, and free association. Where both communities and individuals flourish. To accomplish that, we’re working hard to make web3 accessible for everyone around the world. MetaMask is both a crypto wallet and a gateway to the decentralized web. Our tools help people create communities, play video games, access financial services, make payments, invest in assets, protect against economic turmoil, and more. Our browser extension and mobile platforms meet the needs of millions of users and developers across the world. Originally a humble key manager, today MetaMask serves over 30 million monthly active users as a decentralized application development platform, an aggregator of decentralized cryptocurrency exchanges, and a decentralized identity manager. About the Role MetaMask has experienced explosive user growth over the past year as a cryptographic key manager and web3 application development platform. As this user base continues to grow, an immense amount of trust is being placed in MetaMask as a tool that manages and wields their digital authority, controlling assets, identities and more. It is of highest importance to us that we keep our users as safe and secure as possible. We are looking for a Senior Application Security Engineer to join our rapidly growing security team to help embed security into all phases of the software development lifecycle. You would work closely with development teams and product managers to ensure MetaMask products are designed and implemented to the highest security standards. Consenys’s application security team primarily supports MetaMask with opportunities to expand to additional products in the Consensys family. To apply for this position, you must have: 6+ years of experience building and securing software, including hands-on product or application security experience. Experience securing modern backend systems, web applications, and APIs. Experience performing threat modelling, security design reviews, and vulnerability assessment. Experience securing JavaScript-based applications across web and/or mobile (Node.js, React, React Native preferred). Strong coding skills, with the ability to work directly with engineers to identify and fix vulnerabilities or build secure solutions. Familiarity with Blockchain technology (particularly Ethereum), Decentralized Applications and crypto wallets Solid understanding of the modern web and mobile security landscape, including common attack vectors and mitigations. Strong communication skills, with the ability to influence engineering decisions and collaborate effectively in a remote environment. Self-driven and proactive, comfortable operating in a high-autonomy, distributed team. Alignment with our mission and values. Timezone: Most timezones will work. Regardless of where you are, some overlap with EU and US-Pacific time zones will be necessary. Nice to have: Experience working as a software developer. Deep knowledge of Ethereum (and other blockchains), Decentralized Applications and crypto wallets. Knowledge of smart contract implementation and security. You’re a MetaMask user! Responsibilities Determine the root cause and severity of vulnerabilities reported to us through our bug bounty platform. Interface with ethical hackers, triage reports, and guide product engineering teams to resolution. Document identified vulnerabilities in a way that allows for our engineering team to take quick action. Write code to support the development of security engineering projects, or fix vulnerabilities in MetaMask client applications. This includes the development of AI tooling for vulnerability determination and resolution in order to keep pace with the changing AI-powered vulnerability detection landscape. Assess potential security vulnerabilities within our applications, and work with development teams to ensure remediation in our established SLAs. Support product teams as they develop new features by conducting design reviews, threat modeling, security testing, and code reviews. Identify gaps in MetaMask’s secure software development life cycle (SSDLC), and take initiative leading efforts to address them. Participate and contribute to team meetings, roadmap planning, and discussions. Validate that security patches address reported vulnerabilities and test for any potential bypasses Proactively prevent future occurrences of a vulnerability through developing automation, security controls, and educating developers. Pave your own path in how you want to make MetaMask more secure. Don’t meet all the requirements? Don’t sweat it. We’re passionate about building a diverse team of humans and as such, if you think you’ve got what it takes for our chaotic-but-fun, remote-friendly, start-up environment—apply anyway, detailing your relevant transferable skills in your cover letter. While we have a pretty good idea of what we need, we’re ready for you to challenge our thinking on who needs to be in this role. The salary range listed for this role applies to US-based candidates only. Compensation for candidates based outside the US (including Canada, EMEA, and LATAM) will be determined based on location, experience, and skills during the interview process, and may differ from the listed US range. US pay range (not including bonus, equity or other benefits) $130,000—$218,000 USD In the rapidly evolving Web3 space, we believe that everyone is a builder. This expansive paradigm requires a range of backgrounds, talents, skills, and experiences to influence and shape the future. At MetaMask, this diversity fuels our ability to shift control and redefine the realm of possibility. We are committed to ensuring that our technology empowers people and communities through decentralized technologies. We welcome the range of perspectives and differences and celebrate them. We’re excited to see how your unique skills as a builder can contribute to our vision, drive innovation, and help us shape a more inclusive Web3. MetaMask is an equal opportunity employer. All employment decisions are made without regard to race, color, national origin, ancestry, sex, gender, gender identity or expression, sexual orientation, age, genetic information, religion, disability, medical condition, pregnancy, marital status, family status, veteran status, or any other characteristic protected by law. MetaMask is aware of fraudulent recruitment practices and we encourage all applicants to review our best practices to protect yourself, which can be found on our page. MetaMask may use artificial intelligence (AI) tools to support parts of our recruitment process, such as reviewing applications, screening resumes, or conducting initial candidate assessments. These tools are designed to assist our recruiting team and improve efficiency — they do not replace human judgment. A human recruiter or hiring manager reviews every candidate, and all final hiring decisions are made by people, not AI. It is a requirement of employment in this position that applicants may be required to submit to background and identity verification checks, including but not limited to employment, education, criminal record checks, and other such checks as determined necessary by the company.