Software Testing and Assertions Questions

Core software testing and debugging practices, including designing tests that exercise normal, edge, boundary, and invalid inputs, writing clear and maintainable unit tests and integration tests, and applying debugging techniques to trace and fix defects. Candidates should demonstrate how to reason about correctness, create reproducible minimal failing examples, and verify solutions before marking them complete. This topic also covers writing effective assertions and verification statements within tests: choosing appropriate assertion methods, composing multiple assertions safely, producing descriptive assertion messages that aid debugging, and structuring tests for clarity and failure isolation. Familiarity with test design principles such as test case selection, test granularity, test data management, and test automation best practices is expected.

EasyTechnical

0 practiced

You have a failing test that compares two large JSON objects. Describe how you would write assertion messages and structure the test so the cause of the failure is obvious. Show an example using pytest or JUnit style assertions and list approaches to minimize noise in diffs (filtering, normalized ordering, highlighting key fields).

EasyTechnical

0 practiced

Describe the test pyramid and how it applies to a complex SaaS product. Explain recommended test distribution between unit, integration, and end-to-end tests, and discuss exceptions where you may intentionally deviate from the pyramid (for example, critical UI flows or external compliance requirements).

MediumTechnical

0 practiced

When rolling out a new feature, describe a comprehensive test plan using feature flags and canary releases. Include pre-rollout tests (unit, integration, canary smoke tests), monitoring signals to watch during canary, rollback criteria, and how to automate promotion of the flag when metrics are healthy.

HardTechnical

0 practiced

A CI test fails intermittently under load but passes locally. Propose a systematic debugging plan to determine whether the problem is test flakiness, infrastructure instability, a race condition, or timing. Include what telemetry to collect, how to reproduce locally, and steps to isolate and fix the root cause.

HardTechnical

0 practiced

For a C++ low-level module, design a test plan to validate memory safety and undefined behavior. Include unit tests with AddressSanitizer and UndefinedBehaviorSanitizer, fuzzing harnesses for public APIs, CI integration of sanitizers, and an example unit test that would trigger a common UB such as signed integer overflow or out-of-bounds access to validate the sanitizer catches it.

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