How we went from manual polling and missed deliveries to a 99.6% event-delivery system that saved ₹60–80K per day in re-delivery costs — and reduced WISMO calls by 59%.
Not every merchant has the same bandwidth for integration. The tracking solution was designed from day one as a tiered product — meeting each partner where they were technically.
D2C sellers, regional retailers, ONDC-listed brands. No dedicated tech team. Needed tracking out-of-the-box.
Shopify & ONDC sellers with in-house tech. Wanted to own their customer communication stack.
Decathlon, Croma, Apollo. Dedicated integration teams, existing CRM/marketing stacks. Required richly-structured event feeds.
Before the webhook infrastructure, Blowhorn's OMS relied on a fragmented, semi-manual tracking architecture. The cost of inaction was measurable — daily.
A deliberately tiered design — ensuring 100% of partners got real-time tracking, while giving enterprise clients the programmatic control they needed.
Zero-integration tracking for SMB partners. Toggle-on dashboard with automated templated SMS via Blowhorn's own Twilio-backed communication service. No API keys. No engineering overhead.
Event-driven push system for growth and enterprise partners. Configurable endpoints, rich payloads, retry guarantees. Status propagation from 60 minutes to under 90 seconds.
order_confirmed → out_for_delivery (with rider + OTP) → delivered → delivery_failed → return_initiated. Each with a consistent, versioned JSON schema and backward compatibility guarantee.
Exponential backoff retry (3 attempts: 30s → 2min → 8min), Redis-backed dead-letter queue, and a self-serve dashboard with event logs, manual retry, and endpoint health monitoring.
Each story represents a distinct user need, backed by acceptance criteria and measured outcomes.
The most important architectural decision: a single comprehensive JSON payload across all event types. Partners integrate once, never re-integrate. Fields irrelevant to an event return null — the contract never changes shape.
null, not absent. Predictable contract, zero defensive parsing needed.| Field Group | OFD | DEL | FAIL | RET |
|---|---|---|---|---|
| Core order | ✓ | ✓ | ✓ | ✓ |
| Rider details | ✓ | ✓ | ✓ | null |
| OTP | ✓ | null | null | null |
| Failure reason | null | null | ✓ | null |
| Return details | null | null | null | ✓ |
| Delivery confirmation | null | ✓ | null | null |
Tracked over 12 weeks post-launch across 4 enterprise clients and 15 merchant partners.
An event-driven microservice layer on top of Blowhorn's existing OMS — decoupled from core write paths to ensure zero latency impact on order processing.