What are some common challenges GraphQL developers face when integrating GraphQL APIs with existing systems?

GraphQL Developers often encounter challenges when introducing GraphQL APIs to legacy systems or microservices architectures. These challenges can include managing data consistency across multiple data sources, optimizing query performance to avoid over-fetching or under-fetching data, and ensuring robust security and access control. Successful integration usually requires close collaboration with backend, frontend, and DevOps teams to align data models, caching strategies, and API documentation. Proactive communication and a strong understanding of both the existing infrastructure and GraphQL best practices help mitigate these challenges.