freelancer for firebase firestore apps react streaming ssr react concurrent mode nextjs seo optimization freelancer for multi-tenant saas apps react devtools ai assistant react wasm integration react edge computing react micro-frontends freelancer for realtime dashboard freelancer for biometric time tracking zustand react state library nextjs app development web development https://jasperyshwl.thelateblog.com/36845324/not-known-factual-statements-about-software-developer-kerja-apa