JavaScript Engineer, Fingerprint
More information about location
Device intelligence platform for fraud detection
Be an early applicant
Device intelligence platform for fraud detection
101-200 employees
Be an early applicant
More information about location
101-200 employees
Company mission
To empower developers to build safe and seamless online services.
Role
Who you are
- 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
- Contributions to open-source projects, especially in the JavaScript/TypeScript ecosystem
Desirable
- 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)
- Experience with WebAssembly, browser extensions, or remote debugging
- Familiarity with AWS services such as Lambda, CloudFront, and DynamoDB
- Browser automation or scraping experience
What the job involves
- We’re looking for a JavaScript Engineer to join the team responsible for our browser-side JavaScript agent, CDN integrations, and other performance-critical SDKs
- This is a high-impact role at the intersection of frontend, backend, and security engineering—ideal for someone who thrives in technically demanding environments and enjoys building tamper-resistant, high-performance code that runs in the browser
- 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
Our take
Digital fingerprinting is an essential process in web browsers that tracks the digital address of a device to monitor web activity. This technique facilitates the identification of fraud and spam, as well as warning signs of account takeovers. However, the success of this requires users to accept cookies, a requirement that is easy to avoid.
Fingerprint provides a digital fingerprinting tool that generates a unique identifier of browser activity without requiring the user to accept cookies. The service uses the same WebGL and canvas fingerprinting utilized by existing competitors, but instead of focusing on devices, it identifies web activity. Suspicious activity will result in the identified user being logged in a database, allowing the service to be improved for others.
With this innovative approach, Fingerprint has been able to build up an impressive client roster of over 6000 companies, including 16% of the top 500 websites by traffic. As well as displaying sustained growth through funding rounds, the company has also continued to improve upon its offering - for instance, in Q1 2023 it reported a decrease in iOS false positive and false negative rates by 85%.
Kirsty
Company Specialist at Welcome to the Jungle
Insights
36% employee growth in 12 months
Company
Funding (last 2 of 4 rounds)
Oct 2023
$33m
SERIES C
Nov 2021
$32m
SERIES B
Total funding: $77m
Company benefits
- Equity
- Unlimited vacation, with a minimum vacation days target
- Remote-first: we work asynchronously and respect time-zone differences
- MacBook (you get to keep it after 3 years)
- A small team with a lean hierarchy where you can make a real impact in shaping the company
- Company meet-ups once a year (we went to Mexico City in 2023!)
- Smaller group meet-ups throughout the year
- $600 yearly budget that you can spend to learn new stuff
- Personal development: we give you the freedom to grow and experiment, work on open-source projects and try new things and ideas
Company HQ
Little Italy, Chicago, IL
Leadership
Valentin Vasilyev
(CTO)Valentin worked as a Software Engineer for the first 9 years of their career, before Team Lead roles at Evrone and Machinio.com. They left this role in March 2019 to co-found Fingerprint the following month.
Dan Pinto
(CEO)Previously co-founded Machino, where they were CTO, and has experience in Software Engineering.
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