SLA
A service level agreement: a written promise about uptime or speed, often with refunds or penalties if the promise breaks.
What it tells you about a developer
SLA experience means someone's engineering carried contractual consequences. They have prioritized reliability work against feature work with money on the line, which is a business judgment on top of a technical one. Fluency with SLOs and error budgets usually indicates time at a company with mature operations, and it transfers to any team that runs live services.
An SLA is the contract a company signs with customers, promising numbers like 99.9% uptime. Internally, teams set SLOs, service level objectives, which are the stricter targets they hold themselves to so the contract stays safe. The gap between target and reality is called the error budget, and teams spend it deliberately on risky changes.