When answering the "biggest achievements" question in a job interview, focus on accomplishments that demonstrate measurable business impact and value creation. The most compelling achievements are those where you can clearly articulate the problem you faced, the actions you took, and the quantifiable results that benefited your organization or team. Strong examples might include launching a new product line that generated specific revenue figures, implementing a process improvement that reduced costs by a certain percentage, or leading a team initiative that measurably improved employee retention or productivity.