SLO
Service Level Objective
ELI5 — The Vibe Check
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. Your SLA is the race commitment (external), your SLO is your training target (internal) — usually set a bit stricter so you have a buffer before breaching the SLA.
Real Talk
A Service Level Objective is an internal target value for a service level indicator, such as 'API response time < 200ms for 99% of requests.' SLOs are stricter than SLAs to create an error budget. Violating an SLO triggers action; violating an SLA triggers contractual consequences.
When You'll Hear This
"Our SLO is 99.95% availability — that gives us buffer before hitting the 99.9% SLA." / "The SLO for checkout latency is p99 < 500ms."
Related Terms
Monitoring
Monitoring is keeping a constant eye on your app while it runs — tracking whether it's up, how fast it responds, how many errors it throws, and how much me...
SLA (Service Level Agreement)
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.
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.
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.