📘 Keep tech debt from meaning sloppy insult

What you’ll learn

1. The Debt MetaphorState Cunningham's 1992 loan in his words, separate principal from change-triggered interest, and refuse to call sloppy code debt.On 26 March 1992 Ward Cunningham compared shipping first-time WyCASH+ code to going into debt. A little debt speeds development if you repay it with a rewrite; unpaid, every minute on not-quite-right code is interest. The 1992 paper never prints the label technical debt. The 2009 video rejects writing poorly on purpose. Fowler's 2019 page: interest is extra effort when you change the crufty area, not a calendar charge. The metaphor is a way to talk about cruft, not a claim that it is the most useful metaphor in software.
2. Fowler's QuadrantPlace a piece of debt on Fowler's 2009 grid and name the response that cell requires.Fowler's 14 October 2009 quadrant — written after Uncle Bob's 'a mess is not a technical debt' — splits deliberate/inadvertent from prudent/reckless. Reckless-deliberate is we don't have time for design. Reckless-inadvertent is what's layering?. Prudent-deliberate is we must ship now and deal with the consequences. Prudent-inadvertent is now we know how we should have done it, the inevitable cell and Cunningham's original gap. The question is what kind, and what to do.
3. Smart Bets and PaybackTell Type I from Type II, take only focused or long-term intentional debt, and pay principal by refactoring the hot path in small pieces.McConnell's June 2008 paper: Type I is unintentional; Type II is intentional, then short-term versus long-term. Only focused short-term and long-term debt are really healthy. Unfocused credit-card nicks do not pay off. Time-to-market can justify a named loan. Fowler's refactoring definition is the payoff method. Martin's scout rule plus McConnell's small-slices-in-the-workflow rule beat a cleanup quarter — Construx had not seen a months-long focused debt-reduction staff that made sense.
4. A Debt Decision BriefWrite a one-page debt brief for a launch that reuses an old payments module — place, price, choose among three paths, date the repayment — and leave with three lines on tonight's actual shortcut.Learners work a launch that reuses an outdated payments module. Place it on Fowler's deliberate side; it is prudent only if the cost and the payoff are named. Price principal and interest from two engineering questions. McConnell wants a third path, not only good-versus-dirty. Repayment is a backlog item with an owner; his shop treats debt still open after ninety days as critical. The last move is not a recap: write tonight's loan, interest, and due date, and ask whether anyone will still know it exists in six months.

Grounded in trusted sources

• The WyCash Portfolio Management System — Ward Cunningham, OOPSLA '92 experience report, 26 March 1992 — first-time code as debt; interest as minutes on not-quite-right code; rewrite as repayment
• Ward Explains the Debt Metaphor — Ward Cunningham, 2009 video — never in favor of writing poorly; write code that reflects current, even partial, understanding
• Technical Debt Quadrant — Martin Fowler, 14 October 2009 — reckless/prudent × deliberate/inadvertent; the four quoted labels
• Technical Debt — Martin Fowler, rewritten 21 May 2019 (orig. 1 October 2003) — cruft as interest; interest triggered by change, not by time
• Definition of Refactoring — Martin Fowler, 1 September 2004 — internal structure, cheaper to modify, observable behavior unchanged
• Managing Technical Debt — Steve McConnell, Construx, Version 1, June 2008 — Type I/II, focused vs unfocused, three-path decision, no months-long cleanup staff
• A Mess is not a Technical Debt — Robert C. Martin, 22 September 2009 — a mess is a mess; Fowler's quadrant answers this argument
• Ward Cunningham, The WyCash Portfolio Management System (26 March 1992)

Every Wunder lesson is built from real, reputable sources — never invented.

Related courses