Partial failure in multi-write

Code reviewDistributed systemsSenior–Staff~30 min

Review this JavaScript multi-write notifier.

What a strong answer looks like

Separate real bugs from style. Rank issues by severity, point at the root cause rather than the symptom, and suggest a concrete fix, specific and kind.

0:00 of about 30 min

Mark a line and say what kind of problem it is.0 findings

1async function notifyAll(userIds, message) {

2 if (!userIds.length) return [];

3 const results = await Promise.all(

4 userIds.map((id) => pushService.send(id, message))

5 );

6 await db.markNotified(userIds);

7 return results;

10// caller

11async function broadcast(segment, message) {

12 const ids = await db.usersInSegment(segment);

13 const sent = await notifyAll(ids, message);

14 metrics.incr("push.sent", sent.length);

15 return sent;

16}

Which questions mattered is sealed until you submit. Telling you now would just be handing over the edge cases.