Backend Engineer – MTA

About the role

Resend is building the most accessible email platform for developers. As a Backend Engineer focused on the Mail Transfer Agent (MTA), you will help design, build, and operate high‑volume email transport systems for a rapidly growing user base.

Key responsibilities

• Develop and maintain Resend’s email transport infrastructure, including SMTP delivery, routing, retries, and back‑off strategies.
• Design throttling mechanisms at domain, provider, customer, and IP levels, and manage shared and dedicated IP pools.
• Improve classification of bounces, deferrals, and delivery outcomes, and build debugging tools for delivery issues.
• Translate reputation strategy into backend systems and partner with Trust & Safety to protect the sending network.
• Participate in incident response and be on‑call for critical email services.

Required profile

• Strong backend engineering experience with high‑volume delivery systems.
• Understanding of queues, workers, retries, idempotency, rate limits, backpressure, and distributed systems.
• Interest or experience with SMTP, MTA, DNS, IP pools, and mailbox‑provider behavior.
• Focus on reliability, observability, and operational excellence.

Required skills

• Typescript
• Golang
• AWS
• Postgres
• Datadog
• SMTP/MTA concepts
• DNS
• Queue and worker architectures

What we offer

• Fully remote work with flexible schedules.
• Modern tech stack (Typescript, Go, AWS, Postgres, Datadog).
• Autonomy to ship features quickly.
• Competitive compensation: $150,000‑$170,000 USD.