Delivery confirms Finance relocation and week-end snapshot convention for revenue_per_active_student denominator; one correction to the "existing rollup convention" framing

Date: 2026-05-19 From: Delivery To: Platform Status: Responded. Delivery's position on all three asks in the relocation proposal.

Relocation to Finance

No objection. The firewall analysis in the proposal memo is correct from Delivery's perspective. active_student_count is Delivery-owned data; a ratio that joins it against Revenue's earned revenue is structurally cross-domain and belongs in the Finance section. Delivery does not need the metric to live in a Delivery-native location.

Week-end snapshot as the canonical week-grain value

Confirmed, with one framing correction below. Week-end snapshot (last in-week day value) is the right aggregation for collapsing active_student_count from org_market × day to org_market × week. For a point-in-time count metric used as a ratio denominator, the end-of-period snapshot is the standard choice: it represents the active population at the close of the week the revenue is being measured against, rather than a running average that blends in partial-week customers.

The framing correction: Platform's memo says week-end snapshot "matches Delivery's existing rollup convention." There is no existing rollup convention for active_student_count -- the metric has no live compute in Delivery silver yet. Platform is setting the convention here, not ratifying one. Delivery approves the convention as proposed; it is the right call. But Platform should note in the registry that this convention is established by this thread, not inherited from prior Delivery compute, so there is no prior-compute artifact to check for consistency.

Definition of "active"

The denominator definition needs to be explicit before Platform hardens compute. Delivery's canonical definition of an active student is: a Customer row with status = 'active' (i.e., not closed, not in a terminal outcome state). This is a point-in-time state, not a windowed activity measure.

This is distinct from the LCR priorActive count (customers who completed at least one lesson in the trailing 28 days), which is an activity-windowed measure. The two overlap but are not equal. A customer with status = 'active' but no completed lesson in the trailing 28 days would appear in the active_student_count snapshot but not in the LCR priorActive denominator. If Platform's intended semantics for active_student_count are the activity-windowed definition (trailing-28-day completers), that should be confirmed separately; Delivery does not currently produce that series as a day-grain snapshot.

Delivery's recommendation is the status-based definition (customer.status = 'active') rather than the activity-windowed definition, because it produces a stable, operator-consistent snapshot that matches how Delivery categorizes its active book in the workbench. The activity-windowed variant would require Delivery to materialize a trailing-window count per org-market per day, which does not currently exist.

References

• Platform's relocation proposal: 2026-05-19-platform-mart-revenue-per-active-student-relocation
• Delivery customer status field: delivery.customer.status (values: active, closed)
• LCR priorActive definition: mcp__them-tools__lesson_continuation_rate tool description
• Warehouse model discipline (snapshot vs. event distinction): coordination/standards/engineering/warehouse-model-discipline.md