Software Engineer - Javascript/Typescript

Fingerprint empowers developers to stop online fraud at the source, creating innovative solutions in the fraud detection space. They are seeking a Senior Software Engineer to develop and maintain their browser-side JavaScript agent, focusing on performance, resilience, and compatibility across different browsers.

Responsibilities:

• Build and maintain our browser-side TypeScript/JavaScript agent used for device identification, bot detection, and risk assessment
• Engineer for stealth, resilience, and performance—minimizing footprint, resisting detection, and maintaining compatibility across browsers
• Optimize for both code size and execution speed in complex, adversarial environments
• Stay ahead of browser changes, plugin behaviors, and fingerprinting techniques
• Collaborate with backend, security, and data science teams to align signal capture with detection logic
• Write comprehensive tests and contribute to CI pipelines that ensure functionality across a wide range of platforms and devices
• Contribute to a widely-used open-source project with 24K+ GitHub stars and 25B+ monthly usages

Requirements:

• 3-5 years of JavaScript and TypeScript experience, especially in browser environments
• Deep understanding of browser APIs, DOM behavior, timing attacks, and anti-debugging techniques
• Experience building libraries or SDKs, especially for production or developer-facing use cases
• Strong frontend experience (~80%), with backend familiarity (~20%)
• Proficiency with build tools like Vite, Webpack, Rollup, Esbuild, including code obfuscation and minification
• Experience with modern testing frameworks such as Vitest, Jasmine, Jest, or similar
• Familiarity with security principles, privacy best practices, and adversarial engineering
• Comfortable working in fast-paced environments without rigid specifications
• Strong sense of ownership and autonomy; you enjoy working independently and solving hard technical problems
• Clear written and verbal communication skills in English
• Experience in complex domains like media, gamedev, or security, or on technically demanding browser projects (e.g. Google Docs, Figma, Miro, or 3D browser games)
• Contributions to open-source projects, especially in the JavaScript/TypeScript ecosystem
• Experience with WebAssembly, browser extensions, or remote debugging
• Familiarity with AWS services such as Lambda, CloudFront, and DynamoDB
• Browser automation or scraping experience