freelancer for firebase firestore apps freelancer for cross-browser testing mern stack development company hire full stack developer dotnet developer react micro-frontends freelancer for ai powered web apps freelancer for machine learning integration react query data fetching freelancer for langchain agent apps react 18 features react transitions animations react native https://stern-pinball-machine93681.blog-a-story.com/17431561/top-latest-five-developer-software-careers-urban-news