#Debugging

Database Query Optimization

Rules for writing efficient SQL and ORM queries: indexing strategy, N+1 prevention, and query planning.

Profile Before Optimizing

A measurement-first optimization loop — profile under realistic load, fix exactly one hot spot, re-measure, and keep the numbers in the commit.

Use when: Use when something is slow or resource-hungry and the urge is to start rewriting code that merely looks expensive.

Systematic Debugging Loop

A four-phase debugging discipline — reproduce, isolate, hypothesize, verify — that forbids writing a fix before the root cause is proven.

Use when: Use when a bug, failing test, or unexplained behavior appears and the temptation is to start editing code based on a guess.

Error Handling Discipline

Rules for failing fast, attaching context to errors, deciding catch versus propagate, and eliminating silently swallowed failures.

Use when: Use when writing code with failure modes — I/O, parsing, external calls — or when auditing a codebase for swallowed and contextless errors.