Incident Postmortem Template for Platform Outages: A Practical Playbook

Hook: Your platform just failed — now what?

Outages hurt revenue, erode customer trust and turn on-call teams into fire brigades. If you manage platform infrastructure or run a reseller/hosting service, you need a repeatable, developer-friendly postmortem workflow that converts chaos into improvements. This playbook gives you a copy-paste-ready postmortem template, SLA and monitoring metrics to calculate, prioritized remediation tasks, and customer/internal communication examples tailored for incidents like X's January 2026 outage involving a third-party CDN provider.

Top-line: What this playbook delivers

• A complete postmortem template with all required sections for technical and non-technical stakeholders.
• Actionable SLA metrics to compute impact and error budgets (MTTD, MTTR, availability).
• Prioritized remediation tasks and ownership fields to prevent repeats.
• Communication examples for incident alerts, status page entries and final customer-facing summaries.
• Modern guidance for 2026: AI-Ops, OpenTelemetry, third-party dependency strategies and regulatory compliance considerations.

How to use this template

Use the template as the canonical record for each P1/P0 outage. Start with a one-paragraph summary for executives, then fill in a technical timeline and RCA for engineers. Keep the postmortem factual, time-stamped and actionable: every remediation task needs an owner and a due date.

Incident Postmortem Template (copy-paste-ready)

1) Title and metadata

• Title: [Service] outage on [YYYY-MM-DD] — brief cause/impact (one line)
• Severity: P0 / P1 / P2
• Incident ID: INC-YYYYMMDD-XXX
• Reported: [UTC timestamp of initial report]
• Detected by: (synthetic check / customer reports / monitoring alert)
• Owner(s): Incident commander, Engineering lead, SRE, Communications
• Linked artifacts: runbook, logs, trace links, status page entries

2) Executive summary (3–5 sentences)

One paragraph written for business stakeholders: what happened, impact (users, revenue, compliance), root cause summary, and the highest-priority remediation. Keep it neutral and factual.

3) Scope & customer impact

• Services affected: API, web UI, websocket, CDN, auth, etc.
• Geography affected: global / specific regions
• Users impacted: count and percentage (e.g., 210,000 users / ~15% of MAU)
• Business impact: revenue estimate or qualitative severity, SLA breaches
• Compliance/regulatory impact: GDPR, HIPAA, financial reporting concerns

4) Timeline (chronological, precise UTC timestamps)

Use an event-per-line format. Include detection cue, actions taken, mitigation attempts and recovery point.

• [00:02:34 UTC] Synthetic check failed: 500 responses from origin via CDN
• [00:03:12 UTC] PagerDuty alert triggered to SRE rotation
• [00:06:05 UTC] Incident commander declared P0 and paged on-call leads
• [00:15:47 UTC] Configuration change rollback attempted (no effect)
• [00:30:00 UTC] Identified upstream CDN provider errors — degraded routing observed
• [01:10:23 UTC] Applied origin bypass for critical regions; partial recovery (70% traffic restored)
• [02:05:00 UTC] Full recovery after reverting a specific upstream route; status page updated
• [04:00:00 UTC] Post-incident verification and monitoring watch period started

5) Root cause analysis (RCA)

State the root cause clearly, then list contributing causes and the method used (5 Whys, fault tree analysis, etc.). Distinguish between primary root cause and systemic issues.

• Root cause: Third-party CDN routing failure triggered by provider-side config propagation bug.
• Contributing factors:
  • Insufficient synthetic checks for CDN-edge to origin routing.
  • No automated rollback when third-party edge health degraded.
  • Runbook lacked explicit third-party escalation path and contact list updates.
  • On-call lacked visibility into provider internal status due to missing provider webhooks.
• Method: Correlated traces (OpenTelemetry), CDN vendor logs, packet capture and BGP path inspection.

6) Detection & response analysis

• MTTD (mean time to detect): formula and how measured.
• MTTR (mean time to recover): formula and measured value.
• What worked: on-call escalation, circuit-breakers prevented cascading failures.
• What failed: absence of provider health webhook and missing canary rollback automation.

7) SLA & metrics section (how we computed impact)

This section includes exact formulas, raw numbers and % impacts used to determine SLA breaches.

• Availability calculation: availability = (total uptime window - outage seconds) / total uptime window
• Example: For January 16 outage — 1 hour 55 minutes outage in a 30-day window: availability = (30*24*3600 - 6900) / (30*24*3600) = 99.99% approx. (adjust with actual windows)
• Error budget consumed: If SLA target = 99.95% monthly, compute budget consumed = outage_seconds / seconds_in_month.
• MTTD: first alert to incident declaration = (00:03:12 - 00:02:34) = 38 seconds
• MTTR: detection to full recovery = (02:05:00 - 00:02:34) = 2h 2m 26s

8) Remediation tasks (assign, prioritize, track)

Break tasks into Immediate (0–7 days), Short-term (7–30 days) and Long-term (>30 days). Each task needs an owner, acceptance criteria, and ETA.

• Immediate:
  • Contact CDN account team to confirm root cause, escalate SLA credits — owner: VendorOps — due: 3 days
  • Publish final customer postmortem draft to status page — owner: Communications — due: 2 days
  • Update runbook with provider escalation steps and on-call contact numbers — owner: SRE — due: 7 days
• Short-term:
  • Implement synthetic checks for edge-to-origin routing in all regions — owner: Platform — due: 14 days
  • Add provider webhook integration into incidents channel (PagerDuty/Slack/Teams) — owner: Engineering — due: 21 days
• Long-term:
  • Introduce multi-CDN failover with automated health checks and BGP fallbacks — owner: Network — due: 90 days
  • Adopt chaos testing for third-party failures and run quarterly simulated CDN outages — owner: SRE — due: 120 days

9) Communication plan & examples

Keep communications clear, frequent and role-targeted. Use technical channels for engineers and concise status updates for customers. Below are example templates you can adapt.

Initial public status page message (when incident declared)

Status: Major outage affecting web and API access in multiple regions. Our team is investigating. We will post updates every 30 minutes. Incident ID: INC-YYYYMMDD-XXX.

Internal alert (technical)

[INC-YYYYMMDD-XXX] P0 — Service degraded (API 5xx) — Investigation: Synthetic checks tripping for origin via CDN. Triage on-call to inspect CDN logs and origin connectivity. Suggested immediate action: enable origin bypass for critical routes. PagerDuty triggered.

Customer update during incident (30–60 minutes update)

Update: We are seeing partial recovery after applying routing workarounds. Some users may still experience intermittent errors. We will provide another update in 30 minutes. We apologize for the disruption.

Final customer-facing postmortem summary

Summary: On [date/time UTC], our platform experienced a disruption impacting web and API access. Root cause: a third-party CDN routing issue. Impact: approximately 210,000 users (~X% of MAU) for up to 2h 5m. Remediation: implemented origin bypasses and patching of configuration. Next steps: multi-CDN failover and improved monitoring. We regret the impact and have published our corrective action plan.

10) Status page cadence & examples (best practices)

• Post on incident declaration: brief issue + next update ETA.
• Regular cadence: every 15–60 minutes while unresolved, shorter cadence at peak business hours.
• Upon partial recovery: indicate remaining symptoms and mitigation steps.
• On resolution: post root cause summary and link to full postmortem within 48 hours.

11) Lessons learned and systemic improvements

Convert observations into measurable improvements. Avoid vague statements — attach KPIs and acceptance tests to each lesson to validate change.

• Lesson: Relying on a single CDN introduces systemic risk. KPI: reduce single-CDN dependency to < 30% traffic within 90 days.
• Lesson: Insufficient observability into provider health. KPI: integrate provider webhooks and have 95% alert coverage for edge-origin path checks within 30 days.
• Lesson: Communication cadence unclear. KPI: maintain public status updates every 30 minutes during P0 incidents.

12) Verification & closure

• Verification steps: test synthetic checks, confirm runbook changes, re-run failover simulation.
• Closure criteria: all remediation tasks have owners and due dates; verification completed; postmortem published and circulated to stakeholders.

13) Appendix — raw data and evidence

Attach or link logs, traces, screenshots, packet captures, vendor correspondence and the status page history. Keep these attachments immutable and time-stamped for audits and compliance.

SLA metrics: concrete formulas and examples

Below are the most important SLA and SRE metrics you should calculate in the postmortem. Provide raw inputs and computed values so auditors and legal teams can verify the math.

• Availability (%): (Total time - downtime) / Total time * 100
• MTTD (Mean Time to Detect): average time between incident start and detection across incidents
• MTTR (Mean Time to Recover): average time from detection to full recovery
• Error budget used (%): outage_seconds / seconds_in_sla_period * 100

Example formula use: If you promise 99.95% monthly availability, your monthly allowable downtime is approx. 21.6 minutes. An outage lasting 2 hours consumes >5x the error budget and requires remediation steps and customer credit evaluations.

Modern incident practices and 2026 trends to apply

The incident landscape in 2026 demands a mix of automation, stronger third-party governance and human-centered comms. Recent incidents (e.g., the Jan 2026 high-impact platform outage linked to a major CDN provider) exposed weaknesses in vendor visibility and synthetic testing. Apply these trends:

• OpenTelemetry everywhere: correlate logs, traces and metrics across your stack and third-party hops to shorten RCA time.
• AI-assisted incident drafting: use generative models to summarize timelines and propose RCAs, but always review manually for accuracy and tone.
• Multi-provider architectures: push for multi-CDN/multi-DNS solutions to avoid single points of failure; automate failovers in CI/CD pipelines.
• Zero-trust and secure vendor access: keep vendor escalation channels with least-privilege API keys and an auditable contact matrix.
• Chaos and game days: simulate third-party degradations every quarter to verify runbooks and failovers.

Practical checklist: publish a postmortem if...

• The incident caused a measurable SLA breach or customer-visible disruption.
• There was material business impact (revenue, compliance, major customer complaints).
• The root cause involves an upstream provider that could impact recurrence across customers.

Common anti-patterns to avoid

• Blame-focused language. Keep the tone factual and systems-oriented.
• Vague remediation items without owners or timelines.
• Publishing the postmortem only internally — customers expect transparency after major incidents.
• Relying solely on AI for RCA without human verification.

Sample incident timeline (detailed)

Use this granular template in the Timeline section. Include evidence references to log lines or trace IDs next to each event.

• [00:00:00 UTC] True incident start (first failed request observed) — trace ID: abc123
• [00:02:34 UTC] Synthetic check failed in eu-west-1 — alert id: syn-987
• [00:03:12 UTC] PagerDuty triggered to SRE rotation — on-call: jane.doe
• [00:08:00 UTC] On-call confirmed origin reachable; errors originate at edge — CDN trace: cdn-456
• [00:15:47 UTC] Attempted origin bypass via header override — no change
• [00:30:00 UTC] Vendor status page shows partial service degradation — vendor ticket: VEND-1029
• [00:45:30 UTC] Applied per-region origin bypass for us-east-1 — partial recovery 55%
• [01:10:23 UTC] Full routing update from vendor accepted — recovery progressing
• [02:05:00 UTC] Confirmed full service restoration and monitoring green — end of incident

Final recommendations — what to do in the next 90 days

1. Integrate provider health webhooks into incident channels and ensure vendor escalation steps are in the runbook.
2. Deploy multi-CDN failover with automated health checks and canary policies.
3. Extend synthetic coverage to edge-origin paths and implement threshold-based automatic rollback for deploys that change routing.
4. Run quarterly chaos tests simulating provider-side failures; publish outcomes and corrective actions.
5. Review SLA terms with critical vendors and negotiate stronger SLAs and observability commitments.

Closing: Checklist before closing a postmortem

• All remediation tasks have owners and due dates.
• Acceptance tests and verification steps are defined and executed.
• Public postmortem posted and linked on the status page.
• Communication sent to impacted customers and internal stakeholders.
• Lessons learned session scheduled and recorded.

Takeaways and next steps

Use this template to standardize your incident reviews and turn outages into measurable improvements. In 2026, the expectation is speed and transparency: faster detection via modern observability, resilient architectures that assume third-party failures, and clear customer communication.

Key takeaway: A good postmortem is short on blame and long on measurable follow-ups — owners, dates and verification steps make a difference.

Call to action

Ready to adopt a production-ready postmortem process? Download our editable postmortem template and remediation tracker, or contact our platform team to run a 90-day resilience assessment. Implement this playbook and reduce your MTTR and SLA exposure in 2026.

Related Reading

• How to Choose a CRM That Plays Nicely with Your ATS
• Small-Batch Hair Brands: Scaling Without Losing Quality — Lessons from a DIY Cocktail Success
• Occitanie in 7 Days: Wine, Beaches and Hidden Villas in Southern France
• When an AI Wrote Its Own Code: Lessons for Automating Quantum Software Development
• Vendor Bankruptcy or Debt Reset: How to Protect Your Hosted Services Contractually