Email Infrastructure & Deliverability Engineer

We're looking for an Email Infrastructure & Deliverability Engineer to own the systems that send email at scale for a fast-growing ecommerce lifecycle marketing platform — covering behavioral tracking, personalization, and email/SMS automation. In this role, you'll own the entire email sending infrastructure — from queues and scheduling through delivery, feedback processing, and reputation management across a multi-tenant environment. This is a great opportunity for someone with deep backend infrastructure experience and real email deliverability expertise who enjoys owning critical systems end-to-end, protecting sender reputation at scale, and working autonomously in a small, high-ownership team. Your responsibilities will include: Build and operate high-throughput email sending services, queues, and workers Implement retries, backpressure, prioritization, rate limits, and adaptive throttling Manage shared and dedicated IP pools, domain reputation, warm-up, and traffic routing Build domain onboarding for SPF, DKIM, DMARC, return-path, and tracking domains Process bounces, complaints, unsubscribes, suppressions, and ISP feedback loops Monitor throughput, queue latency, deferrals, bounce rates, complaints, and reputation signals Create automated guardrails that throttle, pause, reroute, or block unsafe sending Diagnose production issues across SMTP, DNS, providers, queues, and mailbox providers Own your systems end to end, including observability and incident response What we expect from you: Strong backend or infrastructure engineering experience Production experience building or operating high-volume email systems, ideally at an ESP or marketing automation platform Deep knowledge of SMTP, bounces, complaints, deferrals, throttling, and mailbox-provider behavior Hands-on experience managing sender reputation across domains and IP pools Strong knowledge of SPF, DKIM, DMARC, DNS, domain alignment, and custom sending domains Experience with queues, distributed workers,