Jan 12 · 6 min read · By this point in the series, authorization should no longer feel like a feature.It should feel like a boundary. — Permissions define who may attempt an action.— Policies define what is valid now.— Invariants define what must never be false. Together,...
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Jan 11 · 5 min read · So far, the system has behaved correctly not because every check succeeded, but because each layer understood where its responsibility ended. This part examines what happens when those boundaries erode—not through negligence, but through convenience....
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Jan 10 · 5 min read · By now, the system is no longer abstract. We are past definitions and isolated boundaries. Three layers are in place—permissions, policies, and invariants—each with a narrow responsibility and a distinct failure mode. What remains is to see them oper...
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Jan 9 · 5 min read · By now, the structure is clear. Permissions answer who may attempt.Policies answer what is valid now. Even together, they are not enough. A system can pass every permission check and every policy gate and still reach an impossible state. That respo...
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Jan 8 · 6 min read · By now, the limits of permissions are no longer abstract. Permissions work precisely because they are small, static, and boring. They express capability in principle—nothing more. They do not know when an action happens, why it happens, or whether it...
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Jan 6 · 5 min read · Up to this point, Django’s authorization system has been deliberately conservative. — Permissions are static.— They are model-scoped.— They express capability, not context. If permissions were meant to answer every authorization question, they would ...
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Aug 1, 2025 · 8 min read · In the last article: Building software that actually has meaning, I briefly introduced DDD and how it helps us reflect our business in code. We do this by understanding the domain/industry/business we are trying to model. One of the strongest ways of...
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Jul 24, 2025 · 5 min read · Domain-Driven Design (DDD) represents a paradigm shift in how we align code with business value. Initially coined by Eric Evans in the book Domain-Driven Design: Tackling Complexity in the Heart of Software, DDD encourages development teams to model ...
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May 30, 2025 · 7 min read · Domain events are a powerful way to decouple parts of your system. Instead of tightly coupling your logic, you can publish events and have other parts of your code subscribe to those events. This pattern is especially valuable in Domain-Driven Design...
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May 9, 2025 · 6 min read · If you've ever worked with a legacy C# codebase, you know the pain of an anemic domain model. You have probably opened an OrderService (all similarities to production code are merely a coincidence) and thought "this file does everything." Pricing log...
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