[igor47]

Unfortunately, Airbnb is a pretty legacy AWS client; when we started using it, VPC was a much less prominent feature. Migrating to a VPC is a very non-trivial process, especially if you have RDS instances outside the VPC

[devonbleak]

I'm in the same boat with most of my AWS workload, was created before IGW was available and keep having the same discussion about migrating :-)