Is Notion or Confluence a single source of truth for decisions?

It can hold one, but the wiki page is only the storage half. Both tools depend on someone manually filing after every decision, and both mix decisions in with everything else. The record works only as long as the filing habit does, which is the part that historically fails.

What should a single source of truth contain for each decision?

The verdict as one imperative sentence, the reason, the rejected alternatives, the owner, and the date, plus a pointer to whatever superseded it if it's been reversed. Anything less can't be re-evaluated later; anything more won't get written.

Why do decision wikis die?

A trust spiral. Filing gets skipped under deadline, the record falls behind reality, someone gets burned following a stale entry, and from then on everyone verifies by asking a person, at which point the wiki is dead weight. The failure is in capture, not storage.

What's a single source of truth for product decisions?

A single source of truth is the one place where every product decision lives with its reason, its rejected alternatives, and its owner, and which the team trusts enough to check before re-litigating. The tool matters less than the property: it must stay current without anyone having to remember to file.

Every team asking this question already has three partial sources of truth: a wiki, a backlog, and a Slack history that quietly overrules both. A single source of truth for product decisions is the one place the team actually checks, because it's complete, current, and carries the why.

Why most attempts fail

The Pragmatic Programmer's DRY principle says every piece of knowledge needs "a single, unambiguous, authoritative representation within a system." Hunt and Thomas meant code, but the rule bites hardest on decisions: the same call represented in a PRD, a thread, and two people's memories will eventually contradict itself, and someone will build against the wrong copy.

So teams stand up a decision wiki. It dies the same way every time: not from bad structure, from stale content. Filing is a manual step that competes with shipping, and shipping wins. Once the record falls behind reality, one bad experience teaches everyone to verify by asking a person instead, and a record nobody trusts is worse than none: it answers confidently and wrongly.

That points at the real definition. A single source of truth isn't a place. It's a property: the record stays ahead of what people believe, or people stop believing the record.

What actually works

One URL per decision. Each decision is a first-class object with a stable link, not a row in a meeting-notes page. If you can't link to a decision, you can't cite it in a review, a PRD, or an argument.

Carry the why and the rejected alternatives. A verdict without its reason can only be obeyed or ignored, never re-evaluated. The rejected options are what stop next quarter's re-litigation. The full anatomy is in our guide to the engineering decision log. The same four fields apply to product calls.

Append, never rewrite. Reversed decisions get a successor entry pointing back at the original. A log you can silently edit is a log you can't trust, and trust is the entire asset.

Filter to decisions that constrain. If an entry wouldn't change what someone builds or plans, it's a diary, not a decision. A short log gets read; a complete one gets ignored.

Solve capture before storage. This is the order teams get wrong. Wire recording into the moment of decision (the decider closes the thread with the verdict, in a fixed format), because any system that depends on later filing is already drifting.

Where Lockstep fits

Lockstep's bet is that the filing step can't be fixed with discipline, so it removes it: decisions are captured from Slack and Notion where they actually happen (Jira, Confluence, and Google Docs are newer), drafted with their reasoning, and approved by the owner in one click. Every decision gets a URL, a history, and delivery to the people and AI agents who touch the work next. We're at design-partner stage, Apache-2.0 if you want to self-host. See how it compares to Notion or Confluence as a decision record.