18.49Final interview drill: one-minute answers

If they ask:

“What is DataWeave?”

Mule's transformation language. I use it to map payloads between external API models and downstream system models, as well as filter/map arrays, perform type conversions and build response objects.

“What's a Mule Event?”

The data moving through the flow: message payload and attributes plus event variables.

“Payload vs vars?”

Payload is the current body/result and often changes after processors; vars are named values I preserve across the event.

“What's a flow?”

A sequence of Mule processors, optionally with an event source like HTTP Listener or Scheduler.

“Why Salesforce Upsert?”

It combines insert/update based on a stable External ID, reducing calls and improving idempotency and concurrency behavior.

“Choice vs Scatter-Gather?”

Choice selects one branch based on a condition; Scatter-Gather executes independent routes concurrently and aggregates their results.

“On Error Continue vs Propagate?”

Continue handles the error and considers the containing scope successful; Propagate runs handling logic but keeps the operation failed and passes the error upward.

“MUnit?”

Mule's native testing framework for setting events, mocking processors, asserting resulting event state and verifying meaningful calls.