Sr./Staff JavaScript Developer - Web SDK

TL;DR

Staff JavaScript Developer (Web SDK): Design, build, and optimize high-performance Web SDK for device fingerprinting, identity verification, and behavior analytics with an accent on browser APIs, security, and cross-browser compatibility. Focus on implementing algorithms for unique device fingerprints, gesture and interaction analysis, and performance optimization under resource constraints.

Location: Brazil - Remote. Remote-first culture — work from anywhere.

Company

Building the most advanced AI Risk Decisioning Platform relied on by banks, fintechs, and digital organizations for fraud, credit, and compliance risk management.

What you will do

• Lead development and maintenance of Web SDK for collecting browser and device data.
• Design algorithms for device fingerprints and behavior insights like gestures, keyboard, and mouse interactions.
• Build CI/CD pipeline with automated cross-browser testing and releases.
• Optimize SDK performance for minimal resource usage and seamless experience.
• Conduct code reviews, mentor juniors, and collaborate with product, design, and QA teams.
• Embed data privacy, security, and innovate in browser-based fraud detection solutions.

Requirements

• Proficiency in JavaScript (ES6+), TypeScript, REST APIs, Git.
• Extensive experience with Web SDKs or libraries for data collection and analytics.
• Deep knowledge of browser environments, APIs, security (privacy, encryption, obfuscation).
• Cross-browser compatibility and modern build tools (Webpack, Babel, Rollup).
• 8+ years web development, 3+ years on SDKs; Bachelor’s in CS or equivalent.
• Proven track record like open-source contributions on GitHub.

Nice to have

• Experience with AI-driven analytics, risk systems, or fraud prevention.
• Familiarity with JavaScript SDKs, gestures, and interaction data processing.
• Prior work in high-scale, distributed environments.

Culture & Benefits

• Mission-driven teams with veterans from Meta, Uber, Citi, Confluent.
• Ownership, impact, and innovation in fraud prevention.
• Competitive salary, equity, 401k; 100% employer-covered US health, dental, vision insurance.
• Remote-first, unlimited PTO, family-friendly culture, team events, offsites.
• AI-first company with engineering focus; unparalleled learning opportunities.