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PROJECT 04 / 05
FAULT-TOLERANT BACKEND
CALLER.WORK
Reliable webhook-driven automated telephony infrastructure.
99.95%
Deliverability
50k+
Monthly Calls
180ms
Response Latency
<2s
Failover Recovery
01. Overview
A rock-solid backend infrastructure built to trigger, monitor, and retry mission-critical outbound calls and SMS verification alerts for enterprise customer support desks.
The Problem
Third-party telephony carriers frequently drop webhooks under high concurrency, causing silent notification failures in critical workflow automations.
The Solution
Architected an idempotent queue-based webhook processing system with automated exponential backoff, dead-letter queues, and OpenTelemetry tracing.
02. Architecture & Engineering
- ▹GCP Cloud Functions and Cloud Pub/Sub handling decoupled message queuing
- ▹Idempotent Redis locks preventing duplicate call initiations
- ▹Distributed structured logging with real-time alerting via Slack webhooks
03. Key Capabilities
- ▹Automatic failover across multiple telecom providers
- ▹Real-time call state webhooks with millisecond execution timestamps
- ▹Comprehensive error reporting and automatic retry queues
- ▹Secure signed webhook verification