OperationsAdvancedSubmodule 10 of 12

Postmortems

Postmortems provides a concrete platform capability that must be configured, secured, validated, observed, and owned throughout its lifecycle within Site Reliability Engineering. It is not an isolated definition: its value appears when it supports measure service from the user perspective, choose a target with business context, use burn rate to guide urgency, restore service before perfect diagnosis, learn without blame, and invest recovered time in removing recurring toil.

Practise Postmortems interview questions

How Postmortems works in production

Study Postmortems in the specific context of Site Reliability Engineering by connecting its mechanism to a production decision. First establish what owns the configuration or state, who or what invokes it, and which dependency must already be available. Then state the requirement, configure the smallest working unit, connect its dependencies, test success and failure, and document operational ownership. Relate the result to the preceding Runbooks concept and the following Capacity planning concept. The final proof is not that a command completed; it is that the intended behavior, control, and recovery path are observable and repeatable.

01

Purpose: provides a concrete platform capability that must be configured, secured, validated, observed, and owned throughout its lifecycle.

02

Dependency context: connect Postmortems in Site Reliability Engineering to the preceding Runbooks concept and the following Capacity planning concept.

03

Validation: prove intended behavior and a controlled failure path with retained evidence.

04

Production ownership: document who changes, observes, approves, and recovers this capability.

Postmortems execution flow

A repeatable sequence for learning, implementing, validating, and operating Postmortems.

  1. 01
    FrameState the concrete problem Postmortems must solve in Site Reliability Engineering.
  2. 02
    InspectRead current configuration, dependencies, identity, state, and operational signals before changing anything.
  3. 03
    ImplementState the requirement, configure the smallest working unit, connect its dependencies, test success and failure, and document operational ownership.
  4. 04
    ValidateTest normal behavior, one realistic failure, and the evidence produced by Postmortems.
  5. 05
    OperateAssign ownership, monitoring, change control, and recovery guidance for the capability.

Site Reliability Engineering module flow

See where Postmortems fits in the wider Site Reliability Engineering operating sequence.

  1. 01
    Measure user signalSite Reliability Engineering stage 1: measure user signal with an auditable result before the next stage begins.
  2. 02
    Compare with SLOSite Reliability Engineering stage 2: compare with slo with an auditable result before the next stage begins.
  3. 03
    Detect budget burnSite Reliability Engineering stage 3: detect budget burn with an auditable result before the next stage begins.
  4. 04
    Respond with runbookSite Reliability Engineering stage 4: respond with runbook with an auditable result before the next stage begins.
  5. 05
    Restore serviceSite Reliability Engineering stage 5: restore service with an auditable result before the next stage begins.
  6. 06
    Learn and remove toilSite Reliability Engineering stage 6: learn and remove toil with an auditable result before the next stage begins.

Build and prove the behavior

  1. Create a minimal Postmortems example inside the create an sre operating model lab.
  2. Record the configuration or command, expected result, observed evidence, and one negative test.
  3. Explain how identity, security, monitoring, and rollback apply before treating the exercise as complete.

Common mistakes and control checks

01

Using default configuration without checking limits, identity, network access, lifecycle behavior, monitoring, or failure recovery.

02

Treating Postmortems as a tool feature instead of a controlled part of the end-to-end Site Reliability Engineering flow.

03

Keeping only a successful screenshot while discarding the configuration, test conditions, logs, and recovery evidence.

Confirm that you can explain and apply it

01What problem does Postmortems solve, how does it work in Site Reliability Engineering, and what is it commonly confused with?

Define the mechanism and ownership boundary first. Explain that it provides a concrete platform capability that must be configured, secured, validated, observed, and owned throughout its lifecycle, then contrast it with the adjacent responsibilities represented by the preceding Runbooks concept and the following Capacity planning concept. Close with a concrete validation signal.

02How would you implement and validate Postmortems for a production workload?

Start from workload constraints and existing state. State the requirement, configure the smallest working unit, connect its dependencies, test success and failure, and document operational ownership. Include identity, dependencies, normal and failure tests, monitoring, and an explicit recovery decision.

03A change involving Postmortems causes a production symptom. What evidence would you inspect and how would you recover safely?

Establish scope and recent change, inspect the native configuration and event or log evidence, test the dependency boundary, apply the smallest reversible mitigation, verify user impact has recovered, and retain the findings for permanent prevention.