Testing Strategy and Error Handling Questions

Combines broader testing strategy for systems with a focus on error handling, resilience, and user experience when failures occur. Topics include designing a testing strategy that covers unit tests, integration tests, end to end tests and exploratory testing, applying the testing pyramid, defining error boundaries and recovery paths, graceful degradation and fallback strategies, user feedback and error messaging, fault injection and resilience testing, logging and observability to detect and reproduce errors, and validating error handling behavior across environments and edge cases.

EasyTechnical

27 practiced

Scenario: You're implementing a checkout flow. Describe how you'd design user-facing error messages and UX for payment failures. Cover messaging tone, technical detail to include/omit, localization, accessibility (screen readers), and how to capture telemetry for these errors for later debugging without exposing sensitive information.

MediumTechnical

33 practiced

Describe how you would use feature flags to manage risk for a new error-handling change that alters fallback behavior. Include a test matrix (flag on/off vs environments), rollout plan, key monitoring and rollback criteria, and how tests interact with feature flags.

MediumTechnical

27 practiced

Implement a basic circuit-breaker class in JavaScript (Node) with states CLOSED, OPEN, HALF_OPEN. The circuit breaker should: track failure counts, open after threshold within a time window, auto-transition to HALF_OPEN after a timeout, and allow a single trial call in HALF_OPEN. You do not need to implement persistence—an in-memory version is fine. Include a brief usage example.

MediumTechnical

34 practiced

Plan a fault injection test for a payment-processing flow in staging. Your plan should include safety controls (to avoid charging real customers), which faults to inject (latency, 5xx, dropped messages), what metrics/alerts to monitor, how to roll back, and success criteria for the exercise.

MediumTechnical

30 practiced

Design a contract testing approach for two microservices (orders and inventory) to ensure that inventory changes do not break order creation. Specify what contracts you would assert, how you'd version them, and where contract tests run in the pipeline. Mention one open-source tool you could use.

Unlock Full Question Bank

Get access to hundreds of Testing Strategy and Error Handling interview questions and detailed answers.

Join thousands of developers preparing for their dream job.