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Bridge Town
Course

Financial models,
as code.

A free, login-gated course for FP&A analysts and finance operators. 14 lessons teaching you to build version-controlled financial models with an AI agent — starting with a field card and a free lesson, no paid tier required.

Syllabus

Syllabus at a glance

14 lessons across four phases — from diagnosing spreadsheet failure to delivering board-ready outputs with full lineage.

Course Dependency Map14 course lessons arranged in four phase rows. Each lesson is a numbered circle connected to the next in sequence.DIAGNOSIS12AGENT OS345CONSTRUCTION678910OPERATIONS11121314
Course dependency map: 14 lessons across four phases — Diagnosis (1–2), Agent OS (3–5), Construction (6–10), and Operations (11–14).

14-module curriculum

Diagnosis Lessons 1-2
01
The Fatal Excel Model

Why spreadsheet models fail and what it costs the business.

02
Models Are Systems

Treating financial models as software: inputs, logic, outputs, and dependencies.

Agent operating system Lessons 3-5
03
Building With the Agent

The four agent loops: build, explain, refactor, and review.

04
Architecture and Separation of Concerns

Four-layer model architecture: data, assumptions, logic, and reporting.

05
Reading the Patterns

Translating Excel formulas into recognizable Python patterns.

Model construction Lessons 6-10
06
The Driver Layer

Data vs drivers vs derived values -- and how to source defensible rationale.

07
Revenue Engines

Customer roll-forward, ARR, expansion, and net new revenue modeling.

08
Cost Models and Unit Economics

Headcount, COGS, sales capacity, and CAC payback.

09
Financial Statements as Outputs

P&L to cash flow to balance sheet -- the connected three-statement model.

10
Testing Financial Logic

Seven tests every financial model should pass before it goes to the board.

Team operations and reporting Lessons 11-14
11
Version Control for Finance Teams

Commits, branches, pull requests, tags, and rollbacks for finance.

12
Code Review for Forecasts

Classifying, diffing, and approving forecast changes as a team.

13
Scenarios as Branches

Base, bull, bear, sensitivity sweep, and variance bridge.

14
Reproducibility, Lineage, and Reporting

Run IDs, board packs, metric lineage, and driver rationale.

The shift

From opaque cell references to named dependency graphs

The same model logic — expressed two ways. On the left: Excel cell references that require tracing every formula to understand a number. On the right: named nodes where every dependency is explicit and every output is traceable.

Excel Grid vs Dependency GraphLeft side shows an Excel-like grid with cryptic cell references. Right side shows the same model as an explicit dependency graph with named nodes: churn_rate and starting_customers feed ending_customers, which feeds q3_revenue.Excel: opaque cell referencesCode: named dependency graphA1B1C1=B2*C3=A1+0.12Q3_Rev=SUM(B2:B14)0.15=A3/C1=VLOOKUP(A2,Sheet2!A:C,3,0)=B3-B1???churn_ratestarting_customersending_customersq3_revenue
Left: Excel cell references require tracing every formula to understand a number. Right: named nodes make every dependency explicit and every output directly traceable.
What you’ll be able to do

Six things you can do when you finish

  • Build a version-controlled financial model that any team member can run and reproduce from a single command.
  • Direct an AI agent to write, refactor, and review model logic — without writing Python from scratch.
  • Separate data, assumptions, logic, and reporting so every board-pack number traces back to a defensible source.
  • Write a test suite that catches the seven most common financial modeling errors before the forecast goes to review.
  • Run base, bull, and bear scenario branches with git — no duplicated workbooks or manual reconciliation.
  • Present board-ready outputs with a run ID and full driver lineage, auditable on demand.
Who this course is for

Built for finance professionals, not software engineers

FP&A lead

Your team manages production models in Excel or Sheets. You want version control, auditability, and faster iteration cycles — without rebuilding everything from scratch.

CFO / Controller

You sign off on the numbers. You want every board-ready output to trace back to a defensible rationale, with a full audit history no spreadsheet can provide.

Strategic finance

You build revenue, cost, and scenario models to support decisions. You want reproducible runs, clean review workflows, and a board pack that explains itself.

Included

What you get with every lesson

14 written lessons

Self-paced written lessons covering the full arc from spreadsheet diagnosis to reproducible reporting.

Field cards

One field card per lesson: key concepts, the core diagram, and the prompts you need to apply the lesson in Bridge Town.

Prompt templates

The four essential prompts of financial model engineering and a cheat sheet of 20 reusable modeling patterns.

Starter packs

Reusable driver-layer, revenue engine, cost engine, three-statement model, and scenario template packs.

Review checklists

PR review checklists and sample pull requests for classifying and approving forecast changes.

Written and maintained by the Bridge Town team at Knightian Labs. Built for the practitioners who live in forecasts — not for software engineers.

Free with login No paid tier required 14 lessons 32 downloadable files
FAQ

Common questions

Is the course free?
Yes. The course is free and accessible immediately after login. All 14 lessons and every downloadable artifact are available with a free Bridge Town account — no paid tier required.
What do I need to know before starting?
Finance domain knowledge. You do not need to know Python. The agent writes the model code; your job is to direct it, review the outputs, and understand what the code does.
What will I be able to build when I finish?
A complete three-statement financial model as version-controlled code, with a test suite, scenario branches, and a reproducible board pack — all built with an AI agent.
What do I get to download?
Each lesson ships a field card (key concepts and prompts), plus cheat sheets, starter packs, and sample pull requests — 32 downloadable files in total across the 14 lessons.
How long does the course take?
Each lesson takes 18–28 minutes to read. The full course is roughly 14 hours of reading. Apply the concepts in Bridge Town between lessons and the total time depends on you.

Start lesson 01 — free

Login with your Bridge Town account to unlock all 14 lessons, field cards, starter packs, and review checklists. No paid tier, no time limit.

Start lesson 01 — free →