Assessing developer productivity in expansive software endeavors has become a pressing concern for both academia and industry, as organizations seek reliable ways to understand how engineering effort translates into business value. Traditional metrics—such as commit frequency, lines of code, or code churn—have been widely adopted but remain problematic, since they conflate inconsequential edits with architecturally significant reshaping and provide little insight into task-level contributions. To address this limitation, we introduce a commit-centric analytic framework that leverages clustering to reconfigure disbursed commit logs into coherent parcels, termed builds, that align more closely with the functional level of development tasks. Unlike prior approaches that combine heterogeneous signals such as issues, reviews, or communication logs, our method relies solely on the structural and temporal properties of commits, making it lightweight and broadly applicable. Each build is evaluated along two orthogonal axes: developer effort and build importance. Effort operationalizes the scale and character of contributions, considering code proprietorship, scope, architectural centrality, novelty, and cadence. Importance quantifies the build’s systemic consequence, integrating scale of alteration, distribution of changes, architectural centrality, complexity, task priority, and proximity to release milestones. The fusion of these axes produces the Fair Developer Score, a composite benchmark reconciling personal exertion with organizational value. Validation employs multiple strategies: correlation with process metrics such as pull-request lead time, rollback incidence, and rework ratios; distributional contrasts between central and peripheral developers; predictive regression to test explanatory power for future activity and defect-prone work; and quasi-experimental A/B designs to gauge responsiveness to environmental shifts. These protocols substantiate the reliability of the framework, confirming that the metric captures both the magnitude of development effort and its impact on the project.