Why Upload Progress Bars Lie: Five Resumable Upload Pitfalls in .NET 10

A progress bar showing 87% can be misleading after a network retry, since client-side byte counters may not match what the server has actually accepted. The article argues that resumable upload protocols can make progress honest by letting the server report its last accepted byte. It lays out a checklist of five common shortcuts that cause incorrect progress, each with a short explanation of why it causes trouble and a sketch of the fix. Examples include answering status queries from server state, returning a 308 instead of a 400 for misaligned offsets, and enforcing 256 KiB multiples for non-final chunks. Code snippets are deliberately truncated, and the article promotes a paid subscription that includes the full project.