SlackMon
@priya
Wrote the cache.
When an engineer leaves, their reasoning walks out with them.
The reasons behind your systems live in people’s heads and in threads nobody linked. Most never make it into a doc. Virgo captures that context while the work happens, and keeps it after the people who created it have moved on.
sourcesADR-31PR #2214#search-engAUTH-77
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The person who knew is gone
A new engineer hits a strange line in the search service. The author left in January, and every trail that should explain it has gone cold.
Left in January
No context in the diff
GitHub
search/auth.ts — PR #2214
Commit by Priya, last October.
Gone cold
SlackTue
#search-eng
The thread scrolled away.
Why is auth cached in search?
I'll leave it alone. Hope it's not important.
Predates the change
Confluence
Search architecture
Last edited before the cache.
In meetings all day
SlackWed
@marco
Half-remembers a latency push.
Doesn't cover it
Google Docs
Onboarding guide
Covers setup, not decisions.
Captured while she was still here.
The cache decision was never one document. It was a ticket, a review, a thread, an ADR, and a pull request, spread over weeks. Virgo connected them into the reasoning graph as each one happened, months before anyone knew the context would be needed.
Your whole team queries one reasoning graph.
Virgo kept the decision while the work happened. One question brings back why the cache exists, from the artifacts Priya left behind.
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Agents inherit the reasoning of engineers who left.
The graph answers the new hire and the agent from the same preserved decisions.
For engineers
Onboard from what the team already decided.
Ask about the system in your own words. The design, the constraint, and the incident behind it come back cited, even when their author is gone.
- The decision: ADR-31, still citable.
- The reason: the latency spike behind it.
- The author: preserved with provenance.
For AI agents
Agents reason from decisions no one is left to explain.
An agent touching the search cache reads ADR-31 and the invalidation rule over MCP. It works within the decision instead of guessing at it.
61%lose 30+ minutes a day searching
Stack Overflow 2024 Developer Survey. The reasoning exists; keeping it reachable is the difference.