Notes from the team building C3X. Cost estimation for Terraform, the economics of cloud infrastructure, and how to ship FinOps tooling without a SaaS gate.
EKS cost is control plane ($73/mo) + worker nodes (the bulk) + EBS + load balancers + NAT + cross-AZ transfer. Here's the full breakdown and where the real savings are, almost all in the nodes.
Flexible Server bills compute by tier (Burstable ~$12/mo, General Purpose, Memory Optimized) + storage. HA doubles compute. Here's how to pick the tier, when to skip HA, and how reservations and stop/start cut the bill.
DTU bundles compute/storage/IO simply; vCore separates them and unlocks Azure Hybrid Benefit and reserved capacity. Here's which is cheaper for your database and when to switch.
Container Apps bills per resource-second and scales to zero; AKS bills node VMs 24/7 and gives full Kubernetes. Here's the crossover and when each is the cheaper, simpler choice.
Cloud Functions 2nd gen runs on Cloud Run, so rates converge, but Cloud Run's concurrency lets one instance serve many requests, making it cheaper for request-heavy workloads. Here's how to choose.
Kinesis scales down to a single shard with no real floor; MSK runs brokers 24/7 ($400+/month for a 3-broker cluster). Here's the crossover by throughput and the Kafka-ecosystem angle.
Azure RIs give up to ~72% off a specific VM size; savings plans give up to ~65% across families with full flexibility. Here's which to pick, how they stack with Hybrid Benefit, and why to commit to baseline.
Athena bills $5/TB scanned and costs nothing idle; Redshift bills for a provisioned cluster (~$793/month per node) or per RPU. Here's the crossover by query volume and how table design cuts both.
Transit Gateway is $0.05/hour per attachment (~$36.50/month each) + $0.02/GB. Here's why it costs more than peering, when the hub is worth it (~4-6 VPCs), and how to cut it.
AWS Backup bills mostly for backup storage (GB-month) plus restore and cross-region copy. The bill grows from retention creep. Here's how the meters work and how to keep backups from piling up forever.
App Service Plans bill per instance-hour by tier (B1 ~$13, S1 ~$70, P1v3 ~$120+/mo) times instances. Apps share a plan for free. Here's how to pick the tier and why consolidating apps is the big saving.
Azure CDN is pure caching billed per GB egress with no base fee; Front Door adds load balancing and WAF for a monthly base plus requests. Here's which to use and why cache hit ratio drives the bill.
Persistent disks bill per provisioned GB-month by type: pd-standard ~$0.04, pd-balanced ~$0.10, pd-ssd ~$0.17. Here's which to use, why you pay for provisioned size, and how to stop over-paying for SSD.
Spot VMs run 60-91% below on-demand for the same machine type, preemptible at any time. Here's what belongs on Spot, how it differs from preemptible, Spot GKE pools, and how to design for preemption.
Standard workflows bill $0.025 per 1,000 state transitions; Express bills per request + duration. For high-volume workflows the gap is 50-100x. Here's which to use and why high-frequency Standard workflows blow up.
Consumption bills per execution and scales to zero; Premium bills ~$150/month per always-on instance for no cold starts and VNet. Here's the crossover and the min-instances trap.
AlloyDB costs more per vCPU than Cloud SQL but is much faster for analytical workloads, so it can need less compute for the same performance. Here's how each bills and which to pick.
Secrets Manager is $0.40/secret/month + API calls; Parameter Store standard tier is free. Here's what the fee actually buys (rotation, cross-account) and the split that cuts a large secrets bill 90%.
Cosmos DB bills by provisioned RU/s (~$0.008 per 100 RU/s-hour) times region count. Over-provisioned throughput and needless multi-region writes are the big overspends. Here's how to right-size and which throughput model to pick.
BigQuery on-demand bills ~$6.25/TB scanned; capacity bills for slots. Here's which model is cheaper for your query volume, and why partitioning and never SELECT * is the biggest saving on either.
Graviton (ARM) instances list ~20% cheaper than x86 with up to 40% better price-performance, across EC2, Lambda, RDS, and more. Here's the discount, where it applies, and how small the migration usually is.
AWS WAF charges $5/month per Web ACL + $1/month per rule + $0.60 per million requests, plus paid add-ons like Bot Control. Here's how the meters stack and how to keep them down.
Azure Blob tiers trade storage price for access price, and each cold tier adds a retention penalty. Here's the full picture, storage rates, access costs, minimum retention, and redundancy, and how to pick the right tier.
GCP charges for egress to the internet, between regions, and even between zones, but not ingress or same-zone traffic. Here's the egress map, the three patterns that drive the bill, and how to cut it.