How AWS-specific your code needs to be depends on which AWS services you're using and how you use them. An EC2 instance is just a Linux system, as is a Lightsai

How AWS-specific your code needs to be depends on which AWS services you're using and how you use them. An EC2 instance is just a Linux system, as is a Lightsail system. Other systems like MinIO and Ceph have S3 interfaces for object storage, so the code could be kept. Operationally you'd need to retrieve it from Amazon S3 and re-store it. RDS is an export, transfer, and import away from being loaded into a normal database server, but that can take quite a bit of time. Getting geo-sensitive DNS and implicit testing of backends out of Route 53 isn't so simple. Getting stuff out of Lambda and onto a commodity platform isn't quick and easy. If you have data in Glacier there's a substantial lead time to recover your first byte.