Job Title: Senior Engineer - SDK

Company Name: RudderStack

Job Details: RemoteFull,Time

Job Url: https://hiring.cafe/viewjob/mmroxifpbhwpspo4

Job Description: Posted 2mo agoSenior Engineer - SDK@ RudderStackView All JobsWebsiteLondon, England, United KingdomRemoteFull TimeResponsibilities:Build SDKs, Improve performance, Ensure reliabilityRequirements Summary:6+ years building production-grade SDKs or JavaScript libraries; strong JavaScript/TypeScript, browser internals, bundlers, performance optimization, testing, and privacy/security.Technical Tools Mentioned:JavaScript, TypeScript, Webpack, Rollup, Vite, ESBuild, Jest, Mocha, Cypress, Playwright, Fetch, XHR, DOM, CSP, GDPR, CCPA, XSS
About the roleThis is a ground-up opportunity to shape how thousands of developers send data into RudderStack — powering the pipelines that move 300+ billion events every month. You’ll own the SDKs that sit at the heart of our platform — the very first component every customer touches.You’ll work with a world-class engineering team tackling deep browser and performance challenges: **cross-browser reliability, bundle optimization, privacy compliance, and real-time delivery at scale**. You’ll learn how data flows from SDKs in the browser to warehouses, through transformations and into AI-ready customer profiles.This role blends craft and impact. You’ll write code that lives inside our customers’ products, powering analytics, personalization, and AI systems behind the scenes.If you’re the kind of engineer who obsesses over performance, **cares about every byte shipped**, and takes pride in building tools developers love — this is your place.Your code will run everywhere. Your users will be developers themselves. And you’ll build the foundation that powers how enterprises interact with their customer data in the AI era.Why This Role MattersEvery RudderStack customer relies on the SDK to move data from their apps to the warehouse.When tracking fails, analytics break. When performance drops, user experiences suffer.You’ll make the invisible visible—ensuring billions of events reach their destinations reliably.Your work will define trust, performance, and developer happiness across the RudderStack ecosystem.The Builder's Mindset We SeekYou care about **craft**—how a few lines of code can impact billions of events.You balance speed with quality and simplicity with reliability.You debug edge cases across browsers with curiosity, not frustration.You see SDKs as a product, not just code.You build with empathy for developers integrating your work in complex environments.What You'll Master HereCross-browser SDK design (modern + legacy support)Lazy loading, tree-shaking, and bundle optimizationFault-tolerant event delivery with retries and offline supportConsent and cookie management under evolving browser restrictionsDeveloper tools and debugging utilities that improve customer experienceObservability and analytics for SDK performance and reliabilityQualifications6+ years of building production-grade SDKs or JavaScript librariesDeep understanding of web browser internals—Fetch/XHR, DOM, Storage, Cookies, CORS, CSP, Service WorkersStrong JavaScript and TypeScript knowledgeExperience with bundlers (Webpack, Rollup, Vite, ESBuild)Proven track record in optimizing performance and reducing bundle sizeStrong testing discipline (Jest, Mocha, Cypress, Playwright)Knowledge of privacy and security (GDPR, CCPA, CSP, XSS, encryption)Excellent documentation and communication skills