SoftwareUnited States2024
Transactional email API and portal developer
A low-latency send API, a deliverability pipeline, and a docs-first portal integrable in minutes.
- Client
- Resend
- Region
- United States
- Sector
- Developer email API + portal
- Engagement
- 2024 · 16 weeks
- Team
- 3 backend · 1 web · 1 platform
- Status
- Shipped
The challenge
Developers want transactional email that is fast to integrate, observable, and lands in the inbox — not a legacy console. Resend needed a clean send API, a deliverability-aware sending pipeline, and a docs-first portal with logs and webhooks.
What we built
The full pipeline, end to end — not a blurb.
- 01API
A TypeScript/Node send API with idempotency, templating, batching, and edge termination.
- 02Pipeline
Queueing and rate shaping with SPF/DKIM/DMARC handling and suppression + bounce processing.
- 03Portal
A docs-first developer portal with API keys, live logs, and webhook management.
- 04Operations
Edge plus Kubernetes with metrics and alerting.
Results
92 ms
send-API p99 at the edge
99.2%
inbox placement on warmed domains
4 min
median time to a developer’s first successful send
240M
messages/month processed at steady state
Powers transactional email for developer-first products.
Have a constraint like Resend’s? Bring us yours.
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