While automation excels at repetitive checks, it lacks the human cognitive ability to make contextual observations, assess subjective qualities like usability, or serendipitously find bugs outside the scripted path. This creates a coverage gap for issues that significantly impact customer satisfaction and business value, which is a core concern for an Agile tester.

Exploratory testing is perfectly suited for this context. It is a simultaneous process of test design, execution, and learning. It allows the tester to investigate the change, its impacts, and potential risks quickly and adaptively within the time constraint, providing rapid feedback without the overhead of formal script creation.

Boundary Value Analysis (BVA) focuses on values at the edges of equivalence partitions. The boundary is at `purchaseAmount >= 100`. The most effective tests use the minimum values on either side of this boundary: one just below ($99.99), one at the boundary ($100.00), and one just above ($100.01). This targets the most likely area for off-by-one errors.

For a safety-critical medical application, rigorous input validation is paramount. The system must handle not only typical data but also erroneous, extreme, or malicious input robustly to prevent incorrect data from being recorded in a patient’s chart, which could lead to harmful clinical decisions. This is a fundamental technical test requirement in this domain.

Visual regression testing automates the comparison of UI screenshots against baseline images. It is specifically designed to catch unintended visual changes, layout shifts, and rendering bugs that unit or API tests cannot detect. Integrating this into the CI/CD pipeline would provide fast feedback on visual integrity.

State Transition Testing is a technique where test cases are designed to execute valid and invalid transitions between states. The scenario describes analyzing a state diagram and covering transitions (e.g., ‘Logged Out’ -> ‘Entering Credentials’ -> ‘Validating’ -> ‘Logged In’), which is the core practice of this technique.

The Golden Master technique involves running the legacy system with a set of inputs to capture its outputs (the ‘Golden Master’). During refactoring, the new code is run with the same inputs, and its outputs are compared to the Golden Master. This provides a safety net to detect behavioral regressions, even in the absence of formal specifications or unit tests.

Maintainability is key in test automation. Absolute XPaths that rely on a precise, positional hierarchy are extremely fragile. Any change to the page layout, structure, or nesting will invalidate the locator and cause test failures, leading to high maintenance costs. More robust locators (e.g., by ID, relative XPath, or custom attributes) should be preferred.

The Test Pyramid advocates for many low-level unit tests (fast, cheap), fewer integration tests, and even fewer high-level UI tests. An inverted pyramid with many UI tests leads to a slow feedback cycle due to long execution times, and the tests are brittle (breaking with UI changes), making them expensive to maintain. This hinders Agile’s need for rapid, reliable feedback.

While automation excels at repetitive checks, it lacks the human cognitive ability to make contextual observations, assess subjective qualities like usability, or serendipitously find bugs outside the scripted path. This creates a coverage gap for issues that significantly impact customer satisfaction and business value, which is a core concern for an Agile tester.0