pagespeed insight React Site error

I'm seeking an expert to resolve performance issues on my React website, as identified by PageSpeed Insights. The issues are affecting the entire site and need urgent attention.

Requirements:
- Experience with React and performance optimization
- Familiarity with PageSpeed Insights and its metrics
- Ability to improve loading times, FCP, and TTI

Ideal Skills:
- Frontend development in React
- Knowledge of web performance best practices
- Experience with tools like Webpack, Lighthouse, or similar

Please provide a detailed plan and estimated timeline.