Make likes system robust: denormalized counter + optimistic UI#85
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Reads no longer collect every like row to count. A denormalized likeCounts table (mirroring commentUrlCounts) keeps the count O(1), and get reads only the counter doc plus the visitor's single membership row, so a viewer's realtime subscription re-runs only when the count or their own like changes. The toggle mutation is replaced with an idempotent setLike(liked): rapid clicks and double-fires converge on the final desired state instead of racing, and idempotent re-sends consume no rate-limit token. liked omitted still toggles for backward compatibility. The button now updates optimistically and serializes writes (one in flight, always converging on the latest intent), reconciling against the realtime query, so like/unlike feels instant and never drifts out of sync. Adds a likeCounts backfill job + migration flag with a read-time fallback so counts stay correct before backfill. https://claude.ai/code/session_01BcpfW29BRVq2KEJYypLVs6
Replace the single-shot flush with a serialized sync loop that keeps the request in flight until the server is driven to the latest intent. Because inFlight stays true across every send, the reconcile effect (gated on !inFlight) can only clear the optimistic override after the server actually reflects the intent — so a fast like/unlike during a request can no longer settle the button opposite to the server. On any failure the optimistic state reverts to the server value and an error is shown. Navigating mid-request abandons the old page's intent while still letting the in-flight write persist, and a new intent that arrives while the lock is held is re-driven once it releases. https://claude.ai/code/session_01BcpfW29BRVq2KEJYypLVs6
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This was referenced May 26, 2026
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Reads no longer collect every like row to count. A denormalized
likeCounts table (mirroring commentUrlCounts) keeps the count O(1),
and get reads only the counter doc plus the visitor's single
membership row, so a viewer's realtime subscription re-runs only
when the count or their own like changes.
The toggle mutation is replaced with an idempotent setLike(liked):
rapid clicks and double-fires converge on the final desired state
instead of racing, and idempotent re-sends consume no rate-limit
token. liked omitted still toggles for backward compatibility.
The button now updates optimistically and serializes writes (one
in flight, always converging on the latest intent), reconciling
against the realtime query, so like/unlike feels instant and never
drifts out of sync. Adds a likeCounts backfill job + migration flag
with a read-time fallback so counts stay correct before backfill.
https://claude.ai/code/session_01BcpfW29BRVq2KEJYypLVs6