Backend Engineer, Core Sending

This is a fully remote position, open to applicants in Europe.

📋 Description

• Develop and manage Resend’s email transport framework.

• Engage in SMTP delivery, MTA systems, routing, retries, backoff strategies, and delivery controls.

• Create systems for throttling at the domain, provider, customer, and IP levels.

• Establish infrastructure for shared IP pools, dedicated IPs, warmup execution, and reputation-aware routing.

• Enhance the way Resend categorizes bounces, deferrals, transient failures, hard failures, and delivery outcomes.

• Develop tools that assist the team in diagnosing delivery issues by customer, domain, mailbox provider, route, IP, message type, and event.

• Contribute to the design of systems that promote safer, more observable, and easier-to-manage sending behavior.

• Convert reputation strategies into backend systems.

• Collaborate with Trust & Safety to implement controls that safeguard Resend’s sending network from misuse.

• Take part in incident response for issues related to sending, providers, and deliverability.

• Be available on-call for critical services.

⛳️ Requirements

• Possess robust backend engineering experience.

• Have experience in email, messaging, notifications, communications, infrastructure, or other high-volume delivery systems.

• Understand queues, workers, retries, idempotency, rate limits, backpressure, and distributed systems.

• Have familiarity or a keen interest in SMTP, MTAs, DNS, bounces, deferrals, IP pools, and mailbox-provider behavior.

• Value reliability, observability, operational excellence, and minimizing blast radius.

• Exhibit low ego, high ownership, and a strong preference for simple systems.

• Have experience with applications that manage a high workload (Exceptional fit).

• Be knowledgeable about email best practices or demonstrate a willingness to learn more about this domain (Exceptional fit).

• Be proficient in Typescript and Golang (Exceptional fit).

🏝️ Benefits

• 100% remote team with flexible working hours.

• Freedom to "just ship it."

• Responsibility for problems and solutions.

• Modern technology stack (Typescript, AWS, Go, Postgres, Datadog).