Full Answer

The maintenance burden for tracking plugins is highest when multiple plugin layers interact. A WooCommerce update requires testing that the tracking plugin still captures all events correctly. A theme update may affect checkout JavaScript. Payment gateway updates can change the redirect flow that purchase event hooks depend on. GTM container updates become necessary when platforms like Meta change their CAPI requirements or Google updates Enhanced Conversions field requirements.

Server-side tracking reduces surface area for breakage: events fire from server hooks that change less frequently than browser JavaScript, and API updates are handled at the server layer rather than requiring per-site GTM container changes. However, server-side solutions still require monitoring — delivery logs should be reviewed periodically to catch API authentication failures or destination-side changes that interrupt event flow.

For agencies managing multiple clients, the maintenance multiplier is significant: each client running client-side plugins needs independent update cycles, whereas server-side infrastructure updates propagate consistently across all client deployments.