Javascript Engineer – IV-V

This is a fully remote position, open to applicants anywhere in the world.

📋 Description

• Collaborate with your teammates to co-manage the design, development, and ongoing upkeep of Confiant's client-side JavaScript SDK.

• Enhance and optimize the internal workings of the SDK to achieve peak runtime performance, reducing execution time, memory usage, and page load impact across a variety of publisher environments.

• Create effective SDK versioning, deployment, and distribution strategies that facilitate smooth rollouts and updates for a diverse customer base.

• Convert security threat intelligence (such as new malvertising techniques and ad injection patterns) into detection and blocking logic at the SDK level.

• Equip the SDK for observability, ensuring that signals, errors, and detection events are reliably transmitted back to Confiant's backend systems.

• Work closely with the security research team to stay proactive against evolving malvertiser tactics and quickly prototype new detection heuristics.

• Perform thorough performance profiling, benchmarking, and regression testing to ensure SDK modifications do not compromise customer experience.

• Set and advocate for SDK engineering best practices, including testing strategies, documentation standards, and release processes.

• Troubleshoot complex and urgent production issues that arise within live ad environments across a wide array of browsers and platforms.

⛳️ Requirements

• Mastery of JavaScript (ES6+) with an in-depth understanding of browser internals, including the event loop, memory model, garbage collection, and execution context.

• Solid grasp of how JavaScript operates within third-party and sandboxed environments, such as iframes, ad slots, and cross-origin contexts.

• Proven track record in building, deploying, and maintaining JavaScript SDKs or embeddable scripts at a production scale.

• Demonstrated capability to enhance performance, focusing on bundle size, parse time, runtime efficiency, and network impact.

• Experience with SDK distribution methodologies, including versioning strategies, CDN delivery, backward compatibility, and graceful degradation.

• Proficient in modern JavaScript tools: bundlers (Webpack, Rollup, esbuild), transpilers (Babel/SWC), and testing frameworks (Jest, Playwright, or similar).

• Comprehensive understanding of browser security models, such as same-origin policy, Content Security Policy (CSP), and cross-origin isolation.

🏝️ Benefits

• Fully Remote

• Unlimited Paid Time Off

• Sabbatical

• Stock Option Plan

• Exceptional Health Care Plans (Medical, Dental & Vision)

• FSA & Commuter Benefits

• Employee Sponsored Disability & Life Insurance

• 401(k) Plan with Automatic Employer Contribution

• Enhanced and Extended Family Leave

• Learning & Development Budget

• Yearly Office Supply Stipend

• Free Global Co-Working Membership