Module 18 — Interview Coding Scenarios
Module 18 — Interview Coding Scenarios
This is the final technical module: the goal is not to make you memorize all Mule XML, but to make sure you can sketch credible code and explain what every part is doing.
The most likely things they may ask you to write are:
1. A basic Mule flow
2. DataWeave transformation
3. SOQL query
4. Choice routing
5. Salesforce Upsert
6. Error handling
7. A small MUnit test
8. A complete mini-integration
The key interview rule is:
If you forget exact Mule XML syntax, write structurally correct pseudocode/XML and explain the architecture clearly.
A good interviewer should care much more that you understand what belongs where than whether you remember every namespace attribute.
18.1Scenario 1 — Build a simple Mule API flowPrompt:18.2What to say while codingDon't silently type.18.3Scenario 2 — DataWeave mappingPrompt:18.4Scenario 3 — Map an arrayPrompt:18.5Scenario 4 — Filter and mapPrompt:18.6Scenario 5 — Handle missing valuePrompt:18.7Scenario 6 — Type conversionInput:18.8Scenario 7 — Conditional business valuePrompt:18.9Scenario 8 — SOQL by External IDPrompt:18.10Scenario 9 — Contact plus AccountPrompt:18.11Scenario 10 — Account with ContactsPrompt:18.12Scenario 11 — Incremental SOQLPrompt:18.13Scenario 12 — Choice routingPrompt:18.14Scenario 13 — More than two Choice branchesBut if CREATE and UPDATE can both use:18.15Scenario 14 — Raise custom business errorPrompt:18.16Scenario 15 — On Error ContinuePrompt:18.17Scenario 16 — On Error PropagatePrompt:18.18Scenario 17 — Error-to-HTTP mappingA clean conceptual design:18.19Scenario 18 — RetryPrompt:18.20Scenario 19 — Don't wrap too much in retryAvoid:18.21Scenario 20 — Parallel callsPrompt:18.22Scenario 21 — Parallel processing of arrayPrompt:18.23Scenario 22 — For Each or DataWeave?Prompt:18.24Scenario 23 — Account then ContactsPrompt:18.25Scenario 24 — What if Contacts partially fail?Say:18.26Scenario 25 — APIKitPrompt:18.27Scenario 26 — MUnit happy-path testPrompt:18.28Scenario 27 — MUnit negative testPrompt:18.29Scenario 28 — MUnit connector failureMock:18.30Scenario 29 — Idempotency test in TypeScriptIf they shift from MUnit to your stronger area:18.31Scenario 30 — Async integration testEndpoint:18.32Scenario 31 — Bulk designPrompt:18.33Scenario 32 — A DataWeave challenge likely to appearInput:18.34Another DataWeave challenge — group by customerInput:18.35What DataWeave syntax should you memorize?These are enough for your interview:18.36What SOQL should you memorize?These three:18.37What Mule components should you be able to name without thinking?Memorize this list:18.38Component selection drill18.39The coding-interview trap: overengineeringPrompt:18.40Another trap: underengineeringConversely:18.41Another trap: exact syntax panicIf you forget whether the attribute is:18.42You are not expected to memorize generated XML namespacesMule XML often includes:18.43What to say if you've never implemented that exact Mule componentFor example they ask:18.44What to say if they ask you to write code from memoryYou can frame it naturally:18.45The mini-project you should be able to build from memoryIf you have time before the interview, practice exactly this one application:18.46The corresponding DataWeaveAccount:18.47The corresponding MUnit storySay:18.48The corresponding external testThat's where you can leverage your strongest coding skill if the discussion moves toward test automation.18.49Final interview drill: one-minute answersIf they ask:18.50The five snippets I would memorizeEverything else can be reconstructed around those.•Module 18 Cheat SheetYou do not need to impersonate someone who has spent five years hand-writing Mule XML.