What must an IBM Blockchain Platform client consider during a Hyperledger Fabric version upgrade?

When upgrading to a new version of Hyperledger Fabric, it's crucial for an IBM Blockchain Platform client to consider required API updates to chaincode. This is because each version of Hyperledger Fabric may introduce changes to the APIs that applications and chaincode use to interact with the blockchain network. If a client does not update their chaincode to be compatible with the new API definitions or functionalities, they may encounter errors or functionality issues that could disrupt service.

Chaincode, which represents the smart contracts deployed on the network, relies heavily on the underlying APIs for proper execution. Hence, ensuring that any functions or methods referenced in the existing chaincode are updated to align with the latest version's specifications is essential for maintaining system integrity and performance.

While other aspects such as user interface design, training needs, and pricing structure may be important considerations, they don't directly impact the technical functionality and compatibility of the core blockchain deployment in the same way that API updates do following an upgrade.