Senior Frontend Engineer (Widget Runtime)

About the role

The Idukki widget runtime is the single biggest piece of code in our customer-facing surface area. It runs on every PDP, PLP, lookbook, story rail and email tile across 80,000+ storefronts and counting. You own its weight, its rendering performance, its accessibility, and the API the rest of the team builds on top of.

What you'll do

• Hold the line on the 37 KB gzipped budget — every new feature gets weighed against impressions
• Drive Core Web Vitals on every customer site: keep CLS < 0.001, INP < 200ms, LCP impact < 50ms
• Build the public widget SDK + storybook + visual-regression harness that the AI/ML and product teams ship against
• Own A11y conformance (WCAG 2.2 AA) and i18n across 10 European + 4 APAC locales
• Run our experimentation framework: variant injection, sticky bucketing, server-side fallback
• Mentor 2-3 engineers; participate in hiring loops

What you'll need

• 6+ years shipping production JavaScript/TypeScript with a deep React + Web Components background
• Demonstrable runtime-performance wins on a high-traffic surface (case study or shipped repo)
• Hands-on with Vite, esbuild, rollup tree-shaking + module-federation tradeoffs
• Has owned an a11y conformance audit end-to-end
• Comfort working async with a globally distributed team

Nice to haves

• Shopify theme + Liquid + checkout-extensibility familiarity
• Prior work on a CDN-distributed JS SDK
• Experience with edge-rendered React (Cloudflare Workers, Fastly Compute)