New SRE team at your company? Here's a 90-day plan I've used twice. It works because it balances 'show immediate value' with 'build for the long term.'

Days 1-14: Observe

Resist the urge to change things. Watch the current system, read existing post-mortems, shadow on-call, talk to engineers about their pain.

Output: a list of the top 5 reliability problems ranked by 'engineering time lost per week.'

Days 15-30: Quick wins