# Background workers

The entry is a tick doing expensive work it did not need to do.

## Fact enrichment is a 20-call serial waterfall [#680] {#enrichment}

Costs: each fact is resolved in turn and each ecosystem call can spend ten
seconds. A slow but reachable Nexus holds one tick for minutes, so the worker
stops observing its configured interval. V-647 covered the duplicate queue
scan, not this.
Revisit when: Nexus gets slow, or when a batch-resolution endpoint exists.
Workaround: an unreachable Nexus is fine. It is the slow-but-answering case
that hurts.