Recursion vs Iteration: A Practical Framework for Choosing the Right Approach

A software developer shares a mental framework for deciding between recursion and iteration when solving programming problems. The key insight is to evaluate three factors: whether the problem is naturally self-similar, how deep the call stack could grow, and whether intermediate state is awkward to pass through recursive parameters. Recursion tends to work well for tree-shaped problems with bounded depth, while iteration is safer when recursion depth could reach thousands of levels and risk a stack overflow. The article illustrates this with a nested-list flattening problem, showing how an iterative solution using an explicit stack requires more bookkeeping than its recursive counterpart. The author argues that thinking in terms of problem shape, depth, and state — rather than syntax — is the intuition experienced developers rely on.