Most people learn async/await in a clean little test project. await GetDataAsync (); Enter fullscreen mode Exit fullscreen mode Looks simple. Feels safe. Then you push to production, traffic hits, and suddenly async/await is quietly wrecking your backend. This isn't theoretical. It's a real failure pattern: thread starvation mixed with blocking async calls causing cascading latency spikes. It Worked Fine Locally We had a typical .NET backend API: ASP.NET Core Web API SQL Server External HTTP calls Async/await everywhere (or so we thought) Simplified version of the code: [ HttpGet ] public IActionResult GetUser ( int id ) { var user = _userService . GetUserAsync ( id ). Result ; return Ok ( user ); } Enter fullscreen mode Exit fullscreen mode If you come from a synchronous background, nothing looks obviously wrong here. Locally? Fast. Stable. No issues.…