Can you highlight particular problems where they become more apparent in PAS over Classic?

[ChadThomsonPSC]

"You said that code problems will become more apparent when using PAS vs. classic. Can you highlight particular problems or patterns (e.g. memory leaks, OS-COMMAND, etc.) and discuss why PAS is different in this regard?"

[ChadThomsonPSC]

One key reason is in Classic each AVM session is a different agent. In PASOE, each session instantiation is a thread on a single agent.
Any un-managed accumulation of objects on a per-session basis will be visible by increase to a single Agent process' memory consumption.

When running migrated ABL code, you'll simply notice memory leaks you already had much more.

While there are analogs in PAS, the trimming of agents in classic should be considered an anti-pattern and is not a habit that should be carried forward.