New 90-Day Full Stack Roadmap Focuses on React 19 and Next.js 15

- React 19, which officially became stable on December 5, 2024, introduces "Actions" to simplify handling data mutations. This feature, along with the new `useActionState` hook, helps manage pending states, responses, and optimistic updates when submitting forms or performing asynchronous operations. - Next.js 15, released in October 2024, now uses the Rust-based bundler Turbopack for local development, which can lead to up to 76.7% faster server startup times and 96.3% faster code updates with Fast Refresh compared to Webpack. A significant breaking change in this version is that `fetch` requests and GET Route Handlers are no longer cached by default to provide more predictable caching behavior. - Unlike traditional libraries like Material UI, shadcn/ui is not installed as a dependency; instead, you use a CLI command to copy the source code of individual components directly into your project. This gives developers full ownership of the code, allowing for complete control and customization without being tied to a package's update cycle. - The Prisma ORM utilizes a central schema file (`schema.prisma`) as the single source of truth for your database structure. From this file, Prisma automatically generates a fully type-safe client, which provides autocompletion in your editor and helps catch errors in database queries at compile time rather than at runtime. - The Vercel AI SDK acts as a unified interface, allowing developers to integrate with various large language model providers like OpenAI, Google Gemini, and Anthropic using a single API. This abstraction simplifies switching between different models and provides pre-built UI hooks like `useChat` and `useCompletion` to handle streaming responses and state management in conversational interfaces. - LangChain.js is a framework for orchestrating complex, multi-step tasks with AI by creating "chains" or "agents". It allows developers to give language models access to "tools," which are functions the AI can call to interact with external data sources or APIs, enabling it to perform actions like web searches or calculations to answer a user's prompt.