This AWS service certainly has its imperfections (e.g. it doesn’t support all AWS resources) but it is easy to set up and can be quite useful too. When you first enable it, Config will analyse the resources in your account and make the summary available to you in a dashboard (example below). It’s a regional service, so you might want to enable it in all active regions.
Config, however, doesn’t stop there. You can now use this snapshot as a reference point and track all changes to your resources on a timeline. It can be useful when you need to analyse historical records, demonstrate compliance or gain visibility in your change management practices. It can also notify you of any configuration changes if you set up SNS notifications.
Config rules allow you to continuously track compliance with various baselines. AWS provide quite a few out of the box and you can create your own to tailor to the specific environment you operate in. You have to pay separately for rules, so I encourage you to check out pricing first.
As with some other AWS services, you can aggregate the data in a single account. I recommend using the account used for security operations as a master. You will then need to establish a two-way handshake, inviting member accounts and authorising the master account to be able to consolidate the results.