Contract-first design and development is not something new. It was formally introduced by Bertrand Meyer as a part of his Eiffel Programming Language design and has appeared in various technical publications since 19861,2. Therefore, understanding contracts from an old-school tool/technology perspective might be helpful to grasp why it it's useful.

What are Persistence Points? Persistence points in Biztalk is the key issue in dealing with Orchestration Performance. The SQL Server does bulk of the job at the backend to keep the BizTalk server running. BizTalk has this inherent behavior of saving the orchestration state to the SQL Server so as to quickly and easily recover from any failures. Persistence points are those points in the orchestration that save the orchestration state to the database.

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In the process of developing an assembly, you often need to deploy, test, modify, and redeploy it repeatedly. In previous versions of BizTalk Server, if you wanted to redeploy an assembly without changing the version number, you first needed to manually stop, unenlist, and unbind artifacts contained in the assembly in BizTalk Server and then remove the assembly from the BizTalk Management (configuration) database. In addition, after redeploying the assembly, you needed to bind, enlist, and start its artifacts in BizTalk Server.