react developer freelancer for supabase postgres apps front end developer back end developer freelancer for cross-browser testing react devtools ai assistant freelancer for headless ecommerce sites freelancer for realtime dashboard react recoil state management zustand react state library freelancer for langchain agent apps react 18 features vue.js development php https://lorenzojzcnw.look4blog.com/74384942/the-5-second-trick-for-developer-software-engineer-salary