Observability Platform  ·  View 06 of 25  ·  People and journeys

Journey — Cut The Bill Without Going Blind

The journey that decides whether the platform survives its second year.

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Engineering director owns the 4% line Goal — Take 30% out of observability spend without losing an incident to it Trigger — Quarterly spend review: $22 per host per month, rising Done when — A cut with a named owner per change and a stated risk per change 1 · See the bill 2 · Find the waste 3 · Decide ◆ moment of truth 4 · Change 5 · Verify What they do Opens per-team scorecard Sorts by unread data Reads reduction ratios Picks tier, rate or budget Teams apply the change Reviews next month What the platform gives Cost per signal, per team Last-queried per service Active series per team Cost preview at the change Retention + sampling as config Spend against MTTD/MTTL How it feels In control Working Guessing Where it hurts Which cut loses an incident? Quota drops data mid-incident What answers it Attribution within 24 h Unread data is the waste class Metric path is not a lever Incident raise with expiry Cost per host, published Journey — Engineering Director: Cut The Bill Without Going Blind The decision phase is the trough because the platform can price every lever but cannot price the incident a cut will lose. That is the question ADR-19 leaves open. v 1.0 · owner Reliability Architecture · date 2026-09

What the platform can and cannot price

  • It can price every lever — retention tier, sampling rate, cardinality budget, query cost — per team and within 24 hours.
  • It cannot price the incident a cut will lose. That asymmetry is the trough, and it is why unread data is promoted as the waste class: it is the one reduction with a measurable argument behind it.

Decisions

  • Query cost is charged to the querying team, not the producing team, so an expensive dashboard has an owner.
  • The metric path is deliberately not a cost lever. Sampling it would save money and would falsify every count in the platform, so the saving is refused rather than offered with a warning.

Assumptions

  • $22 per host per month all-in and ≤ 4% of infrastructure spend are invented targets, defensible for an estate of this shape and to be replaced by the first real bill.
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Solution Architecture v1.0 · Amazon Web Services with open-source collection and storage · Reliability Architecture · 2026-09 · 25 views06-journey-cut-the-bill