BlackTechStartup
BlackTechStartup Builder SchoolCourse 02

Build From the Foundation

Watch the approved Simple Expense Tracker foundation become a first useful build, then see Product Hard Rules protect that build from drift as the work continues.

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Level Beginner builder Format Guided · Self-paced Course goal Understand how a build stays true to the foundation and its hard rules Guidance Builder School Teacher included
MODULE 01
One lesson · Guided build

Start the Build
From the Foundation.

Your Course 1 foundation is finished. Now watch how Builder School uses that exact foundation to start the Simple Expense Tracker without changing the product.

MODULE 01 · ONE COMPLETE JOB

Watch the first build stay tied to the approved foundation.

Builder School does the building for this course example. Follow what happens and notice why every step stays inside the approved product.

One new idea: product drift is when a build quietly moves away from something that was already approved.

We prevent drift by building only what the foundation says and checking the result against it.

  1. Review the foundation carried forward from Course 1.
  2. See the first useful Simple Expense Tracker build.
  3. Notice what was kept out because it was never approved.
  4. Confirm that the process makes sense.
Keep it simple

Builder School shows the correct process and carries the finished state forward automatically.

Course exampleStart From the Foundation Workspace
Ready
From Course 1Official Product Foundation — Final
Carried forward

Simple Expense Tracker foundation is ready.

Builder School builds itFirst Useful Build — Version 1
Finished for you

The first build uses only the approved expense-tracker decisions.

Simple Expense TrackerTotal Spent
$74.40
NameGroceries
Amount$42.15
CategoryFood
GroceriesFood · $42.15
GasGas · $32.25
What to noticeThe build stayed inside the foundation
No product drift
1

The approved features are present.
Add an expense, choose a category, see the list and total, and delete an expense.

2

The approved categories are used.
Food, Gas, Bills, Shopping, and Other.

3

Extra systems were not invented.
No accounts, bank connections, budgets, reports, notifications, payments, or backend.

FinishDo you understand what happened?
Clarity checkpoint

Builder School used the approved foundation, built only what belonged in the Simple Expense Tracker, and checked for drift.

If anything is unclear, use the Teacher. When it makes sense, use the button above.