How to model financial scenarios and sensitivities with AI
Financial scenario modeling is the practice of building multiple versions of your future — a base case, an upside, a downside — and stress-testing your assumptions before a decision locks you in. For most operators, it shows up before a hiring push, a pricing change, a fundraise, or a vendor contract. The question is always some version of: what does our cash position look like in 12 months if X happens instead of Y?
AI feels like a natural fit here because the core mechanics are logical, not creative. You're essentially asking: given these inputs, what do the outputs look like under different assumptions? Large language models are decent at arithmetic, can hold multiple scenarios in context at once, and can explain the logic behind a number in plain English — which is often what you need to communicate findings to a board or co-founder, not just produce a spreadsheet.
ChatGPT, Claude, and Gemini can all contribute meaningfully to this workflow. They can build scenario tables from numbers you paste in, apply sensitivity rules, flag which assumptions move the needle most, and format results in a way that's readable to non-finance stakeholders. The ceiling is that they work on data you bring to them, not data they can pull themselves — and they don't remember anything from the last time you ran the exercise.
How to do it with AI today
A practical walkthrough using ChatGPT, Claude, and other off-the-shelf LLMs — what they're good at, what you'll have to do by hand.
Where this gets hard
The walkthrough above works — until your numbers change, the LLM hallucinates, or you have to re-paste everything next month.
Tired of the friction?
Starch runs the whole workflow on live data — no copy-paste, no hallucinated numbers, no re-prompting next month.
The same workflow on Starch
Starch is an agentic operating system — it builds and runs persistent software on your live business data. For financial scenario modeling, that means an agent builds a live app connected to your actual Stripe revenue and Plaid bank data, not a prompt you re-run against last month's export.
Starch apps for this workflow
See this workflow by operator
The AI stack built for small finance teams.
The AI stack built for the founder's office.
The AI stack built for emerging fund managers.
The AI stack built for small investor relations teams.
The AI stack built for CPG brands.
The AI stack built for DTC founders.
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