From the free book Delta: Closing the Specification Gap (Dhuri, 2026). The PDF is the canonical edition — figures, tables, and code formatting are simplified online.
The following conventions are used throughout this book: One general note: model providers update pricing and capabilities frequently. Where the book mentions a specific cost, context-window size, or model-version capability, that figure is current at the time of writing — check the provider’s pricing page for what it is now. The patterns are stable; the wire-level details are not. A note on the longer code listings: the foundational types the longer listings build on — Money, Result, and the security and idempotency patterns — live as complete, compilable implementations in the companion repository, linked from acuity.press/code. If you are reading on a tablet or e-reader where line wrapping interferes with the layout, the repository is the canonical reference for those implementations. The repository is licensed under the MIT license; reuse the code in your own projects without ceremony.
Convention
Example
Money<USD>, Result<T>, @RequiredArgsConstructor
src/Domain/ValueObjects/Money.cs
Emphasis
Bold
The constraint must come first.
Citation
(Author Year)
(Sajid et al., 2023) — full sources in Appendix J
Purpose LAW N (violet) One of the Ten Laws of Enterprise AI Prompting — structural truths independent of model choice. ix
PATTERN (dark red) Author-constructed illustrative incident. Financial figures are representative. COST OF THIS MISTAKE (dark) Financial and operational impact. Followed immediately by the prevention. ANTI-PATTERN (red/green) Prompting mistake with avoid/use/why structure. QUICK WIN (orange) A timed action (15–45 min) to immediately improve practice. STOP AND THINK (deep blue) A reflection prompt intended to be answered before reading on.
A Note on Practitioner Quotes A note on the practitioner quotes: the green-bordered passages attributed by role throughout this book (for example, “Tech Lead, Insurance Technology platform”) are composite, written by me to summarize concerns and observations I have read repeatedly across the published work on AI-assisted development. They are not transcriptions of any individual. The attributions are role-and-sector only; no specific person, team, or organization is being quoted. A note on the pattern boxes: incidents marked “Pattern” are constructed to illustrate failure mechanisms that recur across published post-mortems and industry reports. They are not transcripts of specific x events at any organization, and they do not draw on confidential information. The dollar amounts, durations, and volumes attached to them indicate realistic ranges for the kind of failure being shown — not measurements of any single incident. This approach is standard in enterprise technical writing. The goal is to make the cost of inaction concrete and credible, not to document a specific event. Any resemblance to a specific organization’s internal incident is coincidental.
Code Example Conventions All code examples are compilable. An example that would not compile as shown is an error — report it (see Errata below). C# examples target .NET 9 / C# 13 unless explicitly noted. Java examples use Java 21 LTS with Spring Boot 3.3.x unless explicitly noted. Comments beginning with ”// —” are explanatory annotations, not production comments.
Errata and Contact To report errors, email errata@acuity.press or visit the book’s page at acuity.press. For reader questions or other author correspondence, write to author@acuity.press. For commercial reproduction beyond what the MIT license on the companion code allows, contact permissions@acuity. press.