Job Summary:
Fingerprint empowers developers to stop online fraud at the source, focusing on innovative solutions in the fraud detection space. They are seeking a JavaScript Engineer to build and maintain their browser-side JavaScript agent, optimizing performance and collaborating with various teams to enhance detection capabilities.
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
Qualifications:
Required:
- Expert-level 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 Webpack, Rollup, Esbuild, including code obfuscation and minification
- Experience with modern testing frameworks such as 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
Preferred:
- 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
Company:
The highest accuracy device identity platform for high-scale applications Founded in 2019, the company is headquartered in Chicago, Illinois, USA, with a team of 51-200 employees. The company is currently Growth Stage.