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I am a Senior Web Performance Engineer with 9+ years of experience optimizing large-scale web apps and high-traffic sites. I specialize in WordPress development, Divi theme customization, and front-end performance engineering focused on Core Web Vitals such as CLS and LCP. I thrive on auditing complex websites, pinpointing bottlenecks, and delivering measurable gains in user experience through techniques like lazy loading, asset preloading, script optimization, and responsive design improvements.\n\nMy experience spans platforms from SiteGround hosting to CDN caching, and I work with modern frameworks including React, Angular, and Vue to stabilize layouts and improve PageSpeed scores on mobile and desktop. I collaborate across product and infrastructure teams to implement performance strategies and deliver clear technical documentation and performance reports.…I am a Senior Web Performance Engineer with 9+ years of experience optimizing large-scale web apps and high-traffic sites. I specialize in WordPress development, Divi theme customization, and front-end performance engineering focused on Core Web Vitals such as CLS and LCP. I thrive on auditing complex websites, pinpointing bottlenecks, and delivering measurable gains in user experience through techniques like lazy loading, asset preloading, script optimization, and responsive design improvements.\n\nMy experience spans platforms from SiteGround hosting to CDN caching, and I work with modern frameworks including React, Angular, and Vue to stabilize layouts and improve PageSpeed scores on mobile and desktop. I collaborate across product and infrastructure teams to implement performance strategies and deliver clear technical documentation and performance reports.

Johnny Ha

Full Stack Developer, Web Developer, Programmer, +2

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I am a Senior Web Performance Engineer with 9+ years of experience optimizing large-scale web apps and high-traffic sites. I specialize in WordPress development, Divi theme customization, and front-end performance engineering focused on Core Web Vitals such as CLS and LCP. I thrive on auditing complex websites, pinpointing bottlenecks, and delivering measurable gains in user experience through techniques like lazy loading, asset preloading, script optimization, and responsive design improvements.\n\nMy experience spans platforms from SiteGround hosting to CDN caching, and I work with modern frameworks including React, Angular, and Vue to stabilize layouts and improve PageSpeed scores on mobile and desktop. I collaborate across product and infrastructure teams to implement performance strategies and deliver clear technical documentation and performance reports.…I am a Senior Web Performance Engineer with 9+ years of experience optimizing large-scale web apps and high-traffic sites. I specialize in WordPress development, Divi theme customization, and front-end performance engineering focused on Core Web Vitals such as CLS and LCP. I thrive on auditing complex websites, pinpointing bottlenecks, and delivering measurable gains in user experience through techniques like lazy loading, asset preloading, script optimization, and responsive design improvements.\n\nMy experience spans platforms from SiteGround hosting to CDN caching, and I work with modern frameworks including React, Angular, and Vue to stabilize layouts and improve PageSpeed scores on mobile and desktop. I collaborate across product and infrastructure teams to implement performance strategies and deliver clear technical documentation and performance reports.

Available to hire

I am a Senior Web Performance Engineer with 9+ years of experience optimizing large-scale web apps and high-traffic sites. I specialize in WordPress development, Divi theme customization, and front-end performance engineering focused on Core Web Vitals such as CLS and LCP. I thrive on auditing complex websites, pinpointing bottlenecks, and delivering measurable gains in user experience through techniques like lazy loading, asset preloading, script optimization, and responsive design improvements.\n\nMy experience spans platforms from SiteGround hosting to CDN caching, and I work with modern frameworks including React, Angular, and Vue to stabilize layouts and improve PageSpeed scores on mobile and desktop. I collaborate across product and infrastructure teams to implement performance strategies and deliver clear technical documentation and performance reports.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Intermediate

Intermediate

Language

English

Fluent

Work Experience

Senior Software Engineer at Uber

March 1, 2023 - July 1, 2025

Optimized large-scale web interfaces and internal dashboards using React, Angular, and TypeScript, reducing page load time by 42% and improving user interaction responsiveness across mobile and desktop platforms. Audited frontend rendering with Lighthouse and Chrome DevTools to identify layout shifts and rendering bottlenecks. Implemented asset optimization techniques including lazy loading, script deferral, and image compression, improving Core Web Vitals scores. Refactored UI components to stabilize layout rendering and reduce time to largest contentful paint by over 38%. Collaborated with platform and infrastructure teams to implement CDN caching and asset delivery improvements, and produced technical documentation and performance reports outlining findings and gains.

Full Stack Software Engineer & Co-Founder at E-Commerce Business

December 1, 2020 - January 1, 2023

Developed and optimized WordPress websites using the Divi theme builder, elevating mobile PageSpeed scores from 58 to 92 through Core Web Vitals optimization. Conducted comprehensive site performance audits, addressing CLS and LCP issues that affected user experience and search ranking. Implemented image optimization, asset preloading, and lazy loading strategies that reduced page load times by 47%. Customized Divi modules and theme settings to stabilize layout during initialization. Managed SiteGround hosting, caching, and CDN configurations to maximize speed and ensured responsive design consistency across devices. Delivered performance documentation and reports detailing improvements.

Senior Web & Mobile Full Stack Engineer at AT&T

June 1, 2018 - December 1, 2020

Engineered responsive frontend systems using Angular, Vue, HTML5, CSS3, and JavaScript for enterprise internal tools and customer management platforms. Improved rendering efficiency by reorganizing component architecture and optimizing asset loading. Implemented code splitting, resource preloading, and asynchronous script loading; reduced layout instability and rendering delays. Authored architecture guides and technical documentation to promote best practices in performance optimization across teams.

Full Stack Developer at T-Mobile

July 1, 2016 - June 1, 2018

Developed responsive web applications using JavaScript, AngularJS, Vue, and modern CSS frameworks to support telecom CRM systems. Improved performance by optimizing API latency and front-end rendering, implemented modular components, and contributed to performance testing and troubleshooting for enterprise systems.