Zabbix tends to perform nicely for small installations, but as the monitored environment grows, one might run into performance problems. A full Zabbix performance discussion is out of scope here, but let's discuss the starting points to having a healthy configuration and the directions for further research:
Monitor only what you really need, as rarely as possible, and keep the data only for as long as really needed. It is common to new users of Zabbix to use default templates as-is, add a lot of new items with low intervals...and never look at the data. It is suggested to clone the default templates, eliminate all that is not needed, and increase the intervals as much as possible. This involves trimming item lists, increasing intervals, and reducing history and trend-retention periods. There are also events, alerts, and other data—we will discuss their storage settings a bit later.
When using Zabbix agents, use active items. Active items will result in a smaller...