When Azure spend jumps unexpectedly, it’s almost always traceable to a specific service, workload, or meter—not a mystery. The most common drivers we see:
- Compute drift: VMs left running, scaling misconfigurations, AKS/VMSS growth, dev/test resources that never shut down.
- Logging & monitoring expansion: Log Analytics ingestion spikes, diagnostic settings enabled broadly, increased retention.
- Backup & storage creep: Vault growth, long retention, snapshots, disks, geo-redundant settings.
- Network and egress: outbound data, NAT Gateway, Firewall usage, cross-region traffic.
Two newer (and increasingly common) cost spike patterns:
AI services token overuse: A public-facing support agent/bot can burn tokens rapidly—especially when it answers questions not relevant to your website or products. We’ve seen customers incur $1,000+ in unexpected AI charges because the endpoint had no rate limiting, filtering, or usage controls.
Storage tiering mistakes (cold → hot): Moving or rehydrating large datasets from cold/archive to hot tier can trigger significant retrieval and transaction costs. We’ve seen cases where a single operational decision led to a spike approaching $40,000—preventable with better lifecycle policy, approvals, and cost estimation.
The good news: these are fixable quickly—with the right triage steps and guardrails.