As a seasoned Software Engineer specializing in frontend development, I bring over 5 years of hands-on experience to the table. My journey has been defined by a commitment to excellence in crafting scalable and robust SPAs (Single Page Applications) using my expertise in React.js. Thriving in agile environments, I have a proven track record of delivering high-quality solutions that meet both user needs and business objectives.In my current role, I enhanced product performance by replacing the legacy UI with a new design system, incorporating lazy loading for components, and transitioning necessary data fetching to the server side. This resulted in a significant improvement, reducing the LCP(Largest Contentful Paint) from 9 seconds to 1.8 seconds.While at Nokia, during my exploration of the OpenLayers library and map implementation, I encountered a challenging performance issue related to rendering maps and a large set of nodes. I successfully identified and resolved the issue by implementing efficient caching techniques, leading to a remarkable 40% reduction in rendering time.During my tenure at QBurst, I embraced the opportunity to mentor and onboard 4 new team members. Additionally, I actively contributed to the development of a robust design system, comprising over 50 reusable components for an e-commerce SPA (Single Page Application). A standout achievement was optimizing the main landing page's performance. I devised a strategy to fetch paginated data from the CMS(Content Management System) and implemented lazy loading for components. This resulted in a significant improvement, reducing the LCP from 7.6 seconds to 1.4 seconds and decreasing blocking time by an average of 300ms.I am committed to professional development and stay abreast of the latest industry trends through continuous learning. I also enjoy providing mentorship to junior developers, fostering a culture of knowledge sharing and innovation.Email: tonycj1996@gmail.comSkills: React / React.js, Next.js, Typescript, React Redux, Redux-Saga, Mobx, styled-components, Emotion, JavaScript (ES6+), webpack, rollup.js, Jest, React Testing Library, Material UI, HTML / HTML5, CSS / CSS3, Sass, SEO (Search Engine Optimization), Jira, Git, GitHub, REST, APIs, Agile