Evaluating the impact of accessibility testing tool usage across the software development lifecycle in student projects

While numerous studies have explored the integration of accessibility into computing courses, including software engineering courses, most focus on awareness-building or post-development WCAG compliance testing, often overlooking the shift-left principle, which advocates for embedding accessibility considerations early in the software development lifecycle, particularly during the design and planning stages. To address this gap, we redesigned a software engineering course to incorporate accessibility from the outset, beginning with requirements elicitation and UX design. Students received targeted training in using accessibility evaluation tools such as Stark and Axe for Figma during the design phase, followed by continued testing in the post-development (testing) phase using tools like AChecker and WAVE. We analyzed student projects to understand common accessibility issues detected and fixed across phases, and compared issue types across tools. Our findings affirm the value of a multi-tool, multi-phase approach: early design checks enable the identification and remediation of low-effort, high-impact issues, thereby reducing rework and freeing bandwidth for more complex development-level fixes. This work provides practical insights for computing educators aiming to meaningfully integrate accessibility into core software engineering curricula and contributes to a broader cultural shift toward building accessible technologies by design.