Techniques are disclosed for monitoring operation of and/or interaction with a website to detect events (“frustration events”). In at least one embodiment, a detection system is disclosed that can monitor a website for the same or unrelated interaction and operation to detect events that affect the performance of a website, while contributing to the frustration of user interaction with the website. The detection system can monitor interaction with and/or operation of one or more documents of a website. Interactions with a website, operations of the website, or a combination thereof, may be assessed with respect to a threshold defining an event. One or more criteria (e.g., a time period) of the event may be assessed for the interactions and operations. Event data may be generated for the event(s) that occur, and the event data may be sent to a host system to adjust operation of the website.