A blameless postmortem focuses on what happened and how to improve the system, not who to blame. It produces concrete action items (fixes, alerts, runbooks) and builds a culture where people report issues early.
Advanced answer
Deep dive
Expanding on the short answer — what usually matters in practice:
Explain the "why", not just the "what" (intuition + consequences).
Trade-offs: what you gain/lose (time, memory, complexity, risk).
Edge cases: empty inputs, large inputs, invalid inputs, concurrency.
Examples
A tiny example (an explanation template):
// Example: discuss trade-offs for "what-is-a-blameless-postmortem-and-why-is-it-use"
function explain() {
// Start from the core idea:
// A blameless postmortem focuses on what happened and how to improve the system, not who to
}
Common pitfalls
Too generic: no concrete trade-offs or examples.
Mixing average-case and worst-case (e.g., complexity).