Why it matters
Prevents one person having enough access to cause or hide a serious incident alone.
How a self-led small team implements it
In a small team, focus on the highest-risk pairs (who deploys code vs. who approves it) rather than trying to segregate everything.
What auditors expect to see
Access review showing no single person holds conflicting critical permissions.
Track A.5.3 in your own Statement of Applicability — mark it applicable, log your justification, and link it to the risk that drove it.
Start your ISMS