Lead generation · 2025
Building a multi-tenant Press-1 platform that holds at 5,000 concurrent attempts
Press-1 is unforgiving infrastructure: nearly all the work happens on calls that never reach a human. This one carries 5,000+ concurrent attempts, detects machines with its own AMD, and bills to six decimal places per tenant.
- Concurrent attempts sustained
- 5,000+
- On the live platform
- Billing precision
- 6 dp
- Per tenant, reconcilable
- AMD licensing cost
- Removed
- Detection built in-house
- Tenant isolation
- Full
- Shared carriers, separate data
The situation
Press-1 campaigns invert the usual economics. A recorded message goes out at enormous volume and only a small fraction of recipients press 1, so almost every unit of infrastructure is spent on calls that will never involve an agent. Anything inefficient gets multiplied by millions of attempts a day.
Off-the-shelf answering-machine detection is licensed per port. At this concurrency the licence cost alone exceeded what it would take to build detection outright — and the licensed detection was not tuned for the specific audio profile of Press-1 traffic anyway.
Multi-tenancy raised the stakes on billing. Tenants share carriers and infrastructure but reconcile independently against their own CDRs, so a rounding error that is invisible on one call becomes a disputed invoice at scale.
What I did
- 01
Designed the concurrency architecture to sustain more than 5,000 simultaneous attempts, with signalling separated from media so the two scale independently.
- 02
Wrote answering-machine detection in-house, tuned against the audio profile of Press-1 traffic specifically, removing per-port licensing from the cost model entirely.
- 03
Built per-tenant billing accurate to six decimal places, so figures reconcile against tenant-side CDRs without dispute.
- 04
Isolated tenants at the data and reporting layer while letting them share carrier capacity, which is where the cost efficiency comes from.
- 05
Instrumented the platform so cost per press-1 — not cost per attempt — is the number operators actually see.