Anti-Patterns and Best Practices
Anti-Patterns
Deleting previous transactions within each task is probably the most damaging anti-pattern. This is a guaranteed PSR issue.
No Run Result or Debug facility is the second anti-pattern. Large clients will insist on manageable engines. Manageable engines mean that an end-user can review the execution. Lack of this will almost certainly create a last-minute task.
Best Practices
A best practice is to intelligently choose how to create/update transactions and clean up previous engine runs. This is highly dependent on the type of transaction so no single solution will work for all.
Understand that the only user interested in the engine is NOT the user interested in the transactions. There is a user responsible for the management of that engine. Build for this user from the initial design. The added benefit is that Production Support personnel will be more capable of supporting your engine – saving you from tons of questions.