AWS build all its tools on separate networks; one cannot import Lambdas into your VPC or EC2. So Lambdas have higher IO when connected from existing VPC, EC2 instances or other Amazon tools.
- Limited execution times.
- I/O bottlenecks.
- Inter-Lambda communication through slow storage like S3, instead of direct network connections.
- No specialised hardware, just CPU and memory, no GPUs and the like.