Category: python

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Immutability and Defensive State Design in Python

python typing · by Adrian Benavides · August 6, 2026 · 8 min read

Frozen dataclasses are the default for domain value objects, but they don't validate at runtime. msgspec.Struct closes that gap with a single type that decodes, validates, and stays immutable across the wire boundary and the domain layer. attrs and cattrs cover the same ground in two libraries, and pydantic only earns its place when the ecosystem integration matters.

Cross-Cutting Concerns Without Constructor Over-Injection

python architecture · by Adrian Benavides · August 3, 2026 · 5 min read

Use contextvars.ContextVar for cross-cutting concerns that almost every service needs, without threading them through every constructor. Covers per-task isolation, structlog and opentelemetry designs, sync-vs-async leaks, and the failure modes that show up in production.

Enforcing Modular Boundaries with Import Linter in Python

python architecture · by Adrian Benavides · July 24, 2026 · 10 min read

Import Linter enforces Python architectural boundaries at near-zero runtime cost. Benchmarked on three real OSS codebases (10k, 20k, 200k lines of Python).

Hexagonal Architecture in Python: Building Decoupled, Testable Systems

python architecture · by Adrian Benavides · July 10, 2026 · 10 min read

Build decoupled, testable Python systems with Hexagonal Architecture. Covers ports, adapters, driven/driving roles, structural typing with Protocol, and the pitfalls of port proliferation, primitive obsession, and infrastructure leakage.

Domain-Driven Design in Python: Preventing the Big Ball of Mud

python architecture · by Adrian Benavides · July 2, 2026 · 12 min read

Apply DDD tactical patterns in Python with immutable value objects, aggregate roots, and bounded contexts (the modular monolith default, the modern tooling landscape, and when DDD is overkill).