Design patterns visual reference poster for software engineers

A 24 by 36 inch portrait-format educational poster titled "Design Patterns — a working reference" in a heavy geometric sans-serif at the top, with a small all-lowercase subtitle "gang of four, distilled" underneath in a muted warm grey. The poster body is a clean 3-by-4 grid of 12 cells separated by fine 0.5pt rules. Each cell contains, from top to bottom: the pattern name in medium weight sans at around 18pt, a small crisp UML-style diagram in vector line-art, and a single-sentence intent in 9pt monospace set in a slightly lower-contrast grey. The twelve cells are: Singleton, Factory Method, Abstract Factory, Builder, Prototype, Adapter, Decorator, Facade, Composite, Observer, Strategy, and Command. Each mini-diagram is intentionally minimal — two or three boxes, one or two arrows — just enough to communicate the shape of the pattern, not a literal UML textbook figure. Inheritance arrows are hollow triangles, composition arrows are filled diamonds, "uses" arrows are simple open arrowheads, and a small legend in the bottom-left corner labels each arrow type in 8pt. The palette is restrained: a deep ink navy around #0B1220 for text and arrows, an off-white paper background around #F5F1E8 with a very subtle 1-inch dot grid at 5% opacity, and a single accent color — a warm vermilion around #D9432F — used only for the arrow arrowheads and a thin rule under the title. No gradients, no shadows, no 3D, no photographic elements. Margins are generous: 1.5 inch outer margin, 0.75 inch gutters between cells. A slim footer strip at the bottom reads "v1 — print at 300 dpi" in 7pt monospace aligned flush right. Overall feel: a swiss-influenced information-design poster — the kind of print that looks at home framed above a senior engineer's monitor next to a Dieter Rams quote. It should read as a genuine working reference, not as decoration, with every element earning its place and the grid letting a viewer scan all twelve patterns at a glance.