Builder Admin has an internal span presentation model for future trace views. It converts completed build spans into rows ordered by start time, with nesting depth, integer millisecond timings, attribution, and copied attributes.
The highlighted completion chain follows the latest-finishing leaf and its ancestors. This is a timing heuristic; it does not calculate a dependency-aware critical path. Missing parents and cyclic parent links terminate traversal. Negative timings display as zero, and sub-millisecond timings round down.
The model does not yet expose a waterfall or trace API. Benchmark retention and operator UI integration remain follow-up work. For recorded span data today, see the performance guide.