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.
A multi-tenant SaaS at 100,000 users, 250 million API requests a month and a 2 TB database costs roughly 6,540 dollars a month on AWS. Here is the full breakdown, and why observability turns out to cost more than the application tier.
An e-commerce store doing 500,000 monthly visits and 25,000 orders costs about 2,190 dollars a month on AWS, which is 9 cents of infrastructure per order. Here is the full breakdown, including why the CDN is a third of the bill.
A streaming service with a 10,000 hour library and a million viewing hours a month costs about 33,680 dollars on AWS, and 89 percent of that is CDN egress. Here is the breakdown, and why bitrate is the only number that really matters.
A serverless backend for a mobile app with 250,000 monthly active users costs about 1,558 dollars a month, and managed authentication is 71 percent of it. Here is the breakdown and the one line worth challenging.
A chat app with 10,000 concurrent WebSocket connections and 20 million messages a month costs about 977 dollars on AWS. Here is the breakdown, plus where managed WebSockets stop being cheaper than running your own.
A fleet of 100,000 devices reporting telemetry every five minutes costs about 1,886 dollars a month on AWS, or 1.9 cents per device. Here is the breakdown, and why message batching is worth more than every other optimization combined.
A multiplayer game with 200,000 monthly players and 3,000 concurrent at peak costs about 8,325 dollars a month on AWS. Here is the breakdown, including why patch downloads cost more than the game servers.
A WordPress site doing 2 million page views a month costs about 825 dollars on AWS, and full-page caching cuts that to around 650. Here is the component breakdown and why the database is the fragile part.
A build farm running 36,000 jobs a month for 120 engineers costs about 1,165 dollars on self-hosted Spot instances, against 2,304 dollars on hosted runners. Here is the breakdown and where the crossover actually sits.
An internal developer platform serving 150 engineers across three Kubernetes clusters costs about 3,069 dollars a month, or 20 dollars per engineer. Here is the breakdown and which lines grow with headcount.
A streaming and batch pipeline ingesting 1 TB a day costs about 5,721 dollars a month on AWS, which is 19 cents per gigabyte. Here is the breakdown, and why the transform step is the cheapest part of it.
A search backend over 20 million documents serving 5 million queries a month costs about 946 dollars on a managed cluster, or 269 dollars self-managed. Here is the breakdown and where the extra 677 dollars actually goes.
A notification service sending 5 million emails, 2 million pushes, and 200,000 SMS a month costs about 2,543 dollars, and SMS is 69 percent of it for 2.6 percent of the volume. Here is the breakdown.
A file sharing service holding 80 TB for 50,000 users with 20 TB of monthly downloads costs about 4,006 dollars on AWS. Here is the breakdown and why tiering storage matters more than anything else.
A service receiving 30 million webhooks a month, processing them with retries, and archiving payloads costs about 506 dollars on AWS. Here is the breakdown, including the 150 dollar mistake almost everyone makes.
A self-hosted headless CMS with 8,000 entries, 25 editors, and 30 million API requests costs about 1,025 dollars a month on AWS, or 41 dollars per editor seat. Here is the breakdown against the hosted alternative.
A REST API handling 30 million requests a month costs 267 dollars a month serverless or 579 dollars on containers. Here is the full breakdown of both, and where the crossover actually sits.
Not all outbound traffic is billable. Every major cloud has a list of destinations where egress is free, and routing through them is one of the cheapest optimizations available. Here is the list and how to use it.
An API response is billed by the byte once it leaves the cloud. Multiply a few hundred wasted bytes by a billion calls and the padding becomes a real line item. Here is how to price a payload.
Splitting a monolith turns function calls into network calls. Those calls are metered, and a fan-out pattern across availability zones can quietly add thousands per month. Here is the arithmetic.
Spreading pods across availability zones buys resilience and costs bandwidth. Kubernetes load balances without regard to zone by default, so most of your service traffic is billed. Here is how to fix it.
A read replica in another zone or region is not just a second instance bill. Every write is shipped over a metered network, and for write-heavy systems the transfer can rival the compute. Here is the breakdown.
Backup storage is cheap and well understood. Backup movement is neither. Cross-region copies, restores, and third-party backup targets all cross metered networks. Here is what each one costs.
Video is the heaviest thing most companies put on a network. One hour of 1080p delivered to one viewer moves several gigabytes, and the per-GB meter does the rest. Here is the cost per viewer, worked out.