01 · Dispatch
RushHour
Parallel offer, tiered escalation
- Median match, NOW lane
- 3.8 s
- NOW radius ladder
- 5 → 10 → 15 → 20 km
- Workers
- Offer expiry 30 s · escalation 60 s
- Exhausted ladder
- Ops queue, never silent expiry
- Patent
- IN 202511047332 (filed)
The obvious way to assign a job is to ask one professional, wait, and ask the next if they decline. It is also the worst way. Every decline costs the full timeout, and the customer pays for a queue they cannot see. Chain five of those together and a burst pipe waits four minutes for someone to look at a phone.
RushHour offers the job to every eligible professional inside the current radius at once and lets them race. First valid acceptance wins; the rest are told immediately that it is over, because a professional who taps and sees nothing happen learns, correctly, to stop tapping.
If nobody accepts, the radius escalates rather than the wait extending. On the NOW lane the ladder runs 5 km → 10 km → 15 km → 20 km, and it stops there on purpose: at Srinagar's measured urban average of 25 km/h, 20 km is already a forty-minute arrival. A ladder that keeps widening is just a slower way to fail.
Two workers drive this — an offer-expiry pass every 30 seconds and an escalation pass every 60. They can race on a tier transition. We dedupe the outcome rather than serialising the workers, because at our volume the occasional jitter costs less than the coordination would. That is a deliberate trade, not an oversight.
When the outer tier is exhausted the job does not quietly expire. It writes an ops-takeover event and lands in a queue a human is looking at. Silent failure is the one outcome the design refuses.