ORIGINAL COMPANY-CONTEXT PRACTICE
Evolve an enterprise extension contract
Original practice scenario inspired by SAP SE's public business context; this is not a reported interview question or a description of its internal systems. A fictional enterprise application exposes an extension callback to customer plugins. You need to add an optional field and later change a required validation rule. How would you release both changes without assuming every plugin upgrades immediately?
Written for independent practice using company context; this is not a verified question from a company interview.
A REASONED APPROACH
Model answer.
Treat the callback payload and its behavioral guarantees as a versioned contract. Adding data and changing required behavior have different compatibility risks, even when both fit in the same JSON object.
Work through it
- Document required fields, unknown-field behavior, error semantics, and supported versions. Add contract fixtures for old and new plugin consumers.
- Introduce the optional field with safe defaults and observe compatibility before enabling it broadly. Avoid requiring consumers to enumerate an exact closed field set unless promised.
- Release the validation change behind a new contract version or explicit capability negotiation, with migration diagnostics and a deprecation window.
Tradeoffs to discuss
- Supporting versions increases maintenance, but forcing a synchronized upgrade across independently managed plugins creates operational risk.
Common pitfalls
- Schema compatibility alone misses behavior changes.
- Silently interpreting an old plugin response under new validation can produce incorrect business actions.