series7 notebooks · 37 plates · about 95 minutes of reading
Learn FinOps, one notebook at a time
I run FinOps for AWS and AI across a large engineering organisation. Most of the job is arithmetic and agreements: what a line on the bill means, who pays for the shared cluster, how much of next year to commit to today. All of that is easier to learn by moving the numbers yourself than by reading about them.
So these seven notebooks come with instruments on every plate, in the order I’d teach the subject. Together they cover roughly the ground of the FinOps Certified Practitioner exam. When you finish, the AI FinOps series applies the same discipline to tokens and GPUs.
The reading path
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What FinOps is
FinOps is the practice of managing the cost of cloud, AI and other technology together: engineering, finance and business share timely cost data and make trade-offs between speed, cost and quality. The FinOps Framework organises it into six principles, a set of personas, three phases (Inform, Optimize, Operate), four domains of 22 capabilities and a Crawl, Walk, Run maturity model. The month-long blind spotEveryone wants something differentInform, Optimize, OperateCrawl, walk, runThe map of capabilities -
How to read a cloud bill
A cloud bill is a dataset of line items, each a usage quantity times a unit price for one resource in one hour or day. The same line carries several costs: list, contracted, billed and effective, which spreads commitments and credits over the usage. Providers export it in their own formats. FOCUS is the open standard that unifies them. Every line is a multiplicationOne line, four costsMillions of rowsThree clouds, three dialectsThe line nobody drew -
Cloud cost allocation
Cloud cost allocation assigns every line of the bill to the team, product or customer that caused it. Account structure and resource tags cover direct costs. Split rules handle shared costs like clusters and support. The result is reported as showback, which informs teams, or chargeback, which moves the money into their budgets. The unlabelled pileTags that stay putSplitting what everyone sharesInside the clusterA report or a charge -
Cloud cost optimisation
Cloud cost optimisation means using less and paying less per unit. Usage comes first: delete idle and orphaned resources, rightsize machines to their real peak load, schedule non-production environments off outside working hours, and move to newer generations. Then commit to the smaller, steadier baseline. The same steps usually cut energy use and carbon too. The waste huntOne size too bigLights off at nightUsage first, then rateThe greener bill -
How commitment discounts work
Cloud providers discount compute when you commit to it. Reserved Instances, Savings Plans and committed use discounts trade a one- or three-year promise to spend a set amount per hour for 30–70% off. Usage above the promise is billed on demand, and promised spend you don’t use is lost. Spot capacity is cheaper again, but can be taken back. The list price is for strangersDrawing the waterlineWhere the savings peakOne year or three?When the money movesCheaper, if you can be interruptedThe flexibility ladder -
Forecasting, budgets and anomalies
Cloud cost forecasting predicts future spend from history, seasonality and business drivers like users or transactions. Budgets turn the forecast into a limit with alerts that fire on the projected month-end, not just on spend so far. Anomaly detection compares each day with its expected range and routes unexpected spikes to the team that owns them. Three ways to guess next monthForecast the business, not the billBudgets that warn earlySpotting the spikeExplaining the miss -
Cloud unit economics
Cloud unit economics divides cloud cost by a unit of business value, such as cost per order, per customer or per thousand requests. Unlike total spend, it shows whether growth is efficient: spend can rise while unit cost falls. A good unit tracks what drives cost, ties to revenue, and gives each team a target it can move. The bill went up. Good?Choosing the unitWhat scale does to oneCost against revenueRunning a team on a unit cost
Questions people ask
- Is this enough to pass the FinOps Certified Practitioner exam?
It covers roughly the same ground: the framework with its personas and phases, allocation, optimisation, commitment discounts, forecasting and unit economics. The exam also uses the FinOps Foundation’s own names for its capabilities, so read the official framework alongside the notebooks.
- Do I need cloud experience to follow it?
Knowing roughly what a virtual machine and a storage bucket are is enough. The first notebook starts from what FinOps is and who does it, and the bill notebook explains each kind of line item from scratch.
- In what order should I read the notebooks?
Top to bottom. Each notebook uses the vocabulary of the one before, so the bill makes allocation easier and allocation makes unit economics easier. If you already know the framework, start at the bill.