wait-on is a versatile Node.js utility that simplifies asynchronous operations, especially when dealing with external resources. It waits for files, ports, sockets, HTTP(S) endpoints, and even custom resources to become available before proceeding. Configure timeouts, intervals, and specific checks to ensure resources are ready. Ideal for test environments, deployment scripts, and continuous integration/continuous delivery (CI/CD) pipelines, guaranteeing dependencies are ready before execution, preventing errors and enhancing reliability.