High Availability: The Concepts
Why systems fail, how uptime is actually measured, and the redundancy patterns that keep a service running when a piece of it breaks.
What you'll actually learn
"Five nines" gets thrown around as a marketing number, but this track starts from what it actually means in practice — 99.999% uptime is just over 5 minutes of downtime a year, a number that reshapes every design decision once you take it literally. You'll see why redundancy alone doesn't guarantee availability (a second server that fails the same way the first one did buys you nothing) and what a real single point of failure looks like once you know how to spot one.
What you'll be able to do
Given a system's architecture diagram, you'll be able to point at the actual single points of failure — not guess at them — and explain specifically what redundancy pattern would remove each one, which is the concrete skill behind every "design for high availability" interview question.
Syllabus
Frequently asked
Roughly 2 hours across 8 hands-on quests — you can go at your own pace and pick up exactly where you left off.
You should be comfortable with Storage: The Foundations, Networking first — the skill tree unlocks High Availability: The Concepts once you've cleared those.
Yes — High Availability: The Concepts is fully available on the free tier, starting with a free first quest and no payment method required to sign up. Plus and Elite remove pacing limits but don't gate any of the High Availability: The Concepts curriculum behind a paywall.
Create a free account and begin your first quest — no card required.
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