In March 2022, a friend asked me to audit his company’s AWS Solution as they were paying far too much on a monthly basis and it was growing rapidly. They were paying ~$16,000 (~£13,300) /month for a small business and growing by ~$1,000 every month.
I had a nosey around Cost Explorer, immediately spotting that the ec2-other costs were eating up a huge portion of the costs, then noticing that there were 40k+ backups in storage and that this was growing daily.
The actual backup policy was reasonable but the key missing point was the lack of a retention policy (or lifecycle policy). A retention policy marks a backup for deletion after a set period of time when the backups are likely no longer useful anyways.
A quick call with the technical team at the company, recommending suitable retention policies for each of the data types, combined with a quick clear-out of the legacy and the costs are down ~$6,000 in the first month (a lot of wastage) and ~$4200 / £3000/month thereafter.
This quick audit, saved the company $56,400 (~£47,200) in the first year alone and will continue to do so for as long as they use AWS.