Jonas Weber
Frontend Developer · Portland, OR · jonas.weber@example.com · linkedin.com/in/jonasweberdev
Summary
Frontend developer with 6 years shipping React/TypeScript product surfaces at scale: performance, accessibility, and design systems. Lifted checkout conversion 12% by taking LCP from 4.1s to 1.8s, and built the WCAG 2.1 AA component library 4 teams ship on. Deep React, TypeScript, and Core Web Vitals; strong testing culture (Playwright, Testing Library) and close designer collaboration in Figma.
Professional Experience
Senior Frontend Developer · Brightcart
Apr 2023 – Present
- Lifted checkout conversion 12% (worth ~$2.1M/yr GMV) by cutting LCP from 4.1s to 1.8s and INP under 200ms — code-splitting, image optimization, and edge-cached rendering.
- Built the design system (38 React/TypeScript components, WCAG 2.1 AA) adopted by 4 product teams, cutting new-feature UI build time 40% and visual bugs 60%.
- Took the checkout flow to zero critical accessibility violations (from 43) ahead of an enterprise client’s audit, protecting a $900K contract renewal.
- Cut frontend regression escapes 70% by introducing Playwright E2E coverage for the 12 revenue-critical flows, gating CI on visual and interaction diffs.
- Halved bundle size (1.4MB to 640KB gzipped) via dependency audits, tree-shaking fixes, and route-level splitting, cutting bounce rate 8% on mobile.
Frontend Developer · Cedar & Pine Interactive
Jun 2019 – Mar 2023
- Shipped 20+ client marketing and e-commerce sites (React, Next.js), with the agency’s first 100/100 Lighthouse performance score becoming its sales benchmark.
- Rebuilt a legacy jQuery admin portal as a React SPA used daily by 3,000 internal users, cutting task completion time 35% in usability testing.
- Introduced TypeScript across the team’s starter kit, cutting production type errors to near zero within 2 quarters.
Projects
Open-source: use-vitals
- Published a React hook library for in-app Core Web Vitals monitoring with attribution; 900+ GitHub stars, used by 3 companies in production.
Technical Skills
- Core: React, TypeScript, JavaScript (ES2024), Next.js, HTML & CSS (Tailwind, CSS Grid), state management (TanStack Query, Zustand)
- Quality & craft: Core Web Vitals (LCP, INP, CLS), accessibility (WCAG 2.1 AA, ARIA), Playwright & Testing Library, design systems, Figma collaboration, CI/CD (GitHub Actions)
Certifications & Education
- B.S. Computer Science, Portland State University — Jun 2019