What reasons can lead to system shutdowns or slowdowns at certain times?

The reasons for stopping or slowing down a Node.js application at a certain time can be as follows:

• Scheduled tasks (cron, timers): running heavy background processes or scheduled tasks.
• Garbage Collection: performance slowdown during intensive memory cleanup.
• Peak load: an increase in the number of requests at certain times, leading to overload.
• External dependencies: delays in database, API, or other service operations.
• Log rotation or backup: system operations affecting performance.
• Network or resource issues: such as insufficient memory, high CPU load.

For diagnostics, profiling, logs, and monitoring should be used to identify the exact cause.