Email Infrastructure & Deliverability Engineer

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, idempotency, rate limiting, SQL, and Redis
• Ability to diagnose blocklists, spam complaints, authentication failures, and reputation changes
• Understanding of how list quality, engagement, spam traps, and customer abuse affect deliverability
• Clear communication and the ability to work autonomously in a small team

Nice to have:

• Experience at an ESP such as Klaviyo, Mailchimp, Braze, Iterable, SendGrid, Mailgun, or Customer.io
• Experience with Amazon SES or MTAs such as Postfix, Haraka, or PowerMTA
• Familiarity with Google Postmaster Tools, Microsoft SNDS/JMRP, feedback loops, and blocklist monitoring
• Experience with Go, Node.js/TypeScript, Kafka, Pub/Sub, Kubernetes, or Prometheus
• Experience using AI coding tools such as Claude Code or Codex

What we offer:

• Interesting project and technical challenges that support both professional and personal growth.
• A long-term project with stability and impact.
• A flexible, results-oriented schedule with hybrid or remote work options.
• A comfortable, modern office in Kyiv with generator and battery backup.
• Competitive salary, medical insurance, and a supportive onboarding/trial period.
• Team-building events, including parties, online activities, picnics, and more.
• The opportunity to work in a Top Employer company (DOU 2025).