What does 99.9% uptime mean for inference?
Together AI
Together AI explains what different uptime tiers (99%, 99.9%, 99.99%) actually require for AI inference services, mapping each to specific failure domains and architectural requirements. 99% requires node-level redundancy within a data center, 99.9% requires full data center failover with live traffic routing to both facilities, and 99.99% requires multi-region deployment with reserved failover capacity. Infrastructure ownership, continuous failover testing, and end-to-end observability determine whether providers can actually deliver their SLA claims when failures occur.
Why it matters
Reliability numbers are easy to publish. We break down what 99%, 99.9%, and 99.99% uptime actually require, the failure domains each tier has to survive, and the questions to ask any inference provider before you commit.
