full stack development front end developer react automatic batching fullstack dev mern stack development company full stack web developer freelancer for multi-language app support responsive web design freelancer for headless ecommerce sites react component-driven development react recoil state management reactjs freelancer react query data fetching technical seo services freelancer https://cashwrnkf.mybuzzblog.com/16200818/how-software-developer-key-skills-can-save-you-time-stress-and-money