A Node.js development company specializes in building fast, scalable, and real-time applications using Node.js, a JavaScript runtime. Node.js is known for its non-blocking, event-driven architecture, making it ideal for applications that require high performance and scalability, such as real-time messaging, online gaming, and streaming platforms. These companies develop custom applications using Node.js to ensure efficient handling of large volumes of data and traffic. Node.js development companies provide services like API development, web app development, and server-side solutions, delivering robust and responsive applications tailored to business requirements.