GraphQL Schema Design: Building Evolvable Schemas is a guest post by Marc-André Giroux about designing GraphQL schemas that can evolve over time without causing breaking changes. The author emphasizes the importance of using object types instead of simpler structures to avoid future-proofing issues, and notes that naming conventions should be specific and descriptive to prevent confusion when introducing new types or fields. Additionally, the author advises against relying on custom scalars and recommends preferring fields and types over them to maintain introspection ability and make changes easier. Finally, the author stresses the importance of understanding the domain being modeled and using GraphQL's type system to shape a stable API that can adapt to changing requirements.