SLA
Service Level Agreement
ELI5 — The Vibe Check
An SLA is a contract between you and your users about how reliable your service will be. 'We promise the app will be up 99.9% of the time.' If you break that promise (too much downtime), there are often penalties or refunds. It's a legal commitment to reliability.
Real Talk
A Service Level Agreement (SLA) is a formal contract between a service provider and customer that defines expected service levels, typically including uptime percentage, response time limits, and penalties for non-compliance. SLAs are the external-facing commitments derived from internal SLOs.
When You'll Hear This
"Our SLA promises 99.9% uptime — we're at risk of breaching it this month." / "Enterprise customers demand a stronger SLA with financial penalties."
Related Terms
Downtime
Downtime is when your app is broken and users can't access it. It costs money, damages reputation, and makes everyone's phone buzz with alerts.
SLI (Service Level Indicator)
An SLI is the actual measurement you track to know if you're hitting your SLO. If the SLO says 'be fast,' the SLI is the actual timer measuring speed.
SLO (Service Level Objective)
An SLO is the internal target you set for how well your service should run. It's like a personal fitness goal vs a race you signed up for.
SRE (Site Reliability Engineering)
SRE is Google's version of DevOps with a more engineering-focused twist.
Uptime
Uptime is how long your service has been up and working without going down. It's usually expressed as a percentage like 99.9%. 'Three nines' (99.