Running External Commands in C# and Wait Until They Finish

A practical guide to running external commands (like PowerShell scripts, Git, Docker) from a C# application using the Process class. Covers setting up ProcessStartInfo, redirecting stdout/stderr with async event handlers, and using WaitForExit() to block until the command completes. Includes a full working example with a countdown script and tips on escaping, output flushing, and execution policy.