How can I track the changes to certain fields for maintaining a comprehensive audit trail?

 In the context of Salesforce, you can try to configure the field history tracking in Salesforce for the custom Object of the client by using these steps which are given below –

Identify the fields

You can try to work with the client so that you can identify the specific fields which they want to track changes for in their custom Object.

Enabling tracking

You can try to enable the field history tracking for the selected fields by navigating to setup> object manager> custom object > fields and relationship.

Customize field history-related list

You can add the “field history” related list to the page layout of the custom object so that you can display the history of changes for tracked fields.

Access field history data

Once the tracking is enabled, then field history data will be automatically stored in the background.

Here is an example given of enabling the history tracking for a custom object field by using the apex code:-

  Schema.SObjectType.CustomObject__c.fields.Field_to_Track__c.trackHistory = true;