Invoice Studio is a modern invoicing web app designed specifically for freelancers and contractors. Built with Next.js, PostgreSQL, and Prisma, it offers a robust solution for managing invoices with ease. Key features include multi-user authentication, client management, and the ability to create invoices with detailed line items. The app also provides analytics and supports server-side PDF export, ensuring that users can generate professional invoices efficiently. With a clean Docker setup, users can deploy the application seamlessly. The user interface is crafted using Tailwind CSS, offering both light and dark modes for a modern look and feel. Additionally, the app includes auto-sequential invoice numbers per client and dashboard metrics that provide insights by client, month, and year. For developers, the app supports unit testing with Vitest and Testing Library, as well as end-to-end testing with Playwright. This comprehensive tool not only simplifies invoicing but also enhances productivity and efficiency for freelancers.