Clarveo is a trading coach tool that analyzes your trade history to identify expensive repetitive patterns, assigns them a name and cost, and provides one testable rule to improve. The service costs €39/month after a free trial and focuses on behavioral analysis rather than entry signals or win-rate promises.
A programmer discovers that fsync() doesn't guarantee data durability the way commonly assumed, as multiple storage layers between application and disk have different definitions of "done". The article explains how write() only puts data in the page cache, not on disk, and how journaling filesystems add complexity to data persistence guarantees.