gof-builder

One-line summary

Separate the construction of a complex object from its representation — letting the same construction process produce different results, and replacing "telescoping constructors" with a fluent, readable assembly.

When to use this skill

• An object has many constructor parameters (more than ~4), several of which are optional.
• Construction proceeds in steps (build the burger, then add toppings, then wrap it) and the steps may vary.
• You want callers to read like a recipe rather than fight a constructor signature.
• The Kotlin DSL idiom — html { head { … } body { … } } — is a builder.

When NOT to use this skill

• The constructor takes 1–3 parameters and a single call is clearly readable.
• The language already gives you a better tool — Kotlin's named arguments + default parameter values eliminate Builder for most cases. Reach for Builder only when the construction is genuinely staged (intermediate validation, type-safe step ordering).
• You're building a single immutable value object — data class with named args is almost always enough.

When to choose Builder over Factory (gof-factory)