Postmortem

Postmortem is looking at why the system allowed the incident to happen and drag on rather than looking for the person who made the latest mistake. Separate root causes from concomitant factors, and formulate actions with the owner, the duration, and the verifiable risk reduction.

What is Postmortem and Why is it Necessary?

Definition and rapid introductory

Postmortem is a structured meeting and document after an incident, release, or failure in a product. The goal is to understand what happened, why, and how to avoid recurrence. Often found in development, operations, support services outside of IT. The result is not blame, but improved processes and overall product safety.

Why it is important to the product

If you don’t take mistakes apart and document solutions, problems accumulate, solutions are lost, and the same rakes come back. Competent postmortems teach the team to reflect and openness, form stable processes.

Example: After a SaaS service subscription crash, the team collects postmortem: records where the failure occurred (e.g., an error in the integration of payments), finds the cause (an undocumented API change), suggests countermeasures (monitoring mechanisms, improving documentation).

Classic Postmortem Template

Basic structure of the document

In practice, a short and extended form of postmortem-document is distinguished. The minimum structure is as follows:

1. Brief description of the incident
2. Date and time of the event
3. Influence: Who was affected, how was it manifested
4. Detailed analysis of causes
5. Final Actions: What Has Been Done to Eliminate
6. Proposals for prevention
7. Accountability and timelines
8. Open questions

Example of structure (adapt to your command)

1. Incident: massive rollback of payment on March 3, inaccessibility of the client office
2. When: 3.03.2024, from 13:20 to 14:40
3. Impact: 15% of users unable to log in, support calls rise
4. Reason: Merge of an incorrect fix without tests
5. Actions: manual payment recovery, customer feedback ?
6. Prevention: mandatory tests in CI, release checklist
7. Responsible: back-end team, deadlines for making changes until 7.03

For more on postmortem (Atlassian) templates

Checklist for high-quality postmortem

Before postmortem

1. Record the facts in chronological order without evaluation
2. Get everyone involved in the case.
3. Collect logs, metrics, chat records
4. What happened from the perspective of the user and the business

During the discussion

1. Speak the facts, avoid accusations
2. Check all hypotheses on sources: code, logs, documentation
3. Write down each step: what, when, who, why
4. Notice what worked well - the best findings are worth fixing

After postmortem

1. Record the results, make a short summary
2. Appoint those responsible for the changes
3. Make a public decision if it is your company’s policy.
4. Add Post-Analytic Tasks to Tracker

Detailed checklist and ready-made forms (SRE Google)

Common errors and anti-patterns of postmortem

Major mistakes

1. Evaluation judgments and blame-finding
2. Blurred actions such as “increase responsibility”
3. Deficiency of specificity: no date of correction or responsible
4. Conduct for the sake of a tick - the document goes to the table, is not applied
5. No exchange of results with the team

An example of an anti-pattern: After a service drop, the team writes general wording without specifics: “improve testing,” “be more careful,” but does not allocate time or resources to real work.

How to Introduce Postmortem Culture in a Team

Minimum steps

1. Show the benefits for the team: increased transparency, fewer errors
2. Give a comfortable template, save postmortems in public access
3. Make short appointments immediately after the incident (up to 1 day)
4. Encourage Openness: Publicly Discuss Your Mistakes First
5. Start small: template, checklist – and gradually expand the practice

Example of implementation

In a small team, incidents were discussed verbally before, so agreements were lost and similar failures were repeated. The team enters a short postmortem only for events above the agreed threshold. After several cycles, it checks not the number of documents, but the implementation of corrective actions and the recurrence of the same risk factors.

FAQ by postmortem

**When is an incident considered worthy of postmortem? If a significant number of users are affected, SLAs are violated, there has been financial or reputational damage. Minimum criteria can be set in the team.

Who should participate in the postmortem? Those involved in the incident, as well as representatives of related functions (development, support, product).

**Do I need to share the results publicly? Not always, but within the team. In large services, they often share with customers – they increase trust.

How not to go in search of the guilty? ***** Focus on the process, not the personalities. Write the wording: it was not the person who made the mistake, and the process did not protect against the error.

How long does it take to prepare postmortem? On average, 1-2 hours plus a meeting, if you collect facts in advance.

**How do you know if the postmortem measures are implemented? Put tasks in the tracker, set deadlines, check status on retro.