# Low Level Design
All Low Level Design notes →1 — Exception Design
Looks at how to design exception hierarchies and error-signaling contracts so that failures are informative and recoverable rather than opaque.
low-level-design error-handling-and-reliability book
2 — Validation Strategies
Surveys strategies for validating input and state at system boundaries versus deep within business logic, and where each belongs.
low-level-design error-handling-and-reliability book
3 — Defensive Programming
Examines defensive programming techniques for guarding against invalid state and unexpected input without over-defending against impossible cases.
low-level-design error-handling-and-reliability book
4 — Immutability
Explains how immutable objects eliminate mutation after construction, closing off a whole class of concurrency and state-corruption bugs.
low-level-design error-handling-and-reliability book
5 — Value Objects
Introduces value objects as small, immutable types defined by their attributes rather than identity, and where they should replace bare primitives.
low-level-design error-handling-and-reliability book