Role Overview

This is a backend infrastructure role focused on building reliable, high-throughput email sending systems and maintaining strong email deliverability. You will design and operate multi-tenant email infrastructure while protecting domain and IP reputation across customers and mailbox providers.

What You’ll Do

- 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’re Looking For

- 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.
- Robust 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 with email service providers 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 designing or operating large-scale email infrastructure and deliverability systems.
- Experience using AI coding tools such as Claude Code or Codex.

Key Skills Backend Engineering | Email Infrastructure | SMTP | Email Deliverability | SPF | DKIM | DMARC | DNS | Redis | SQL | Queues | Distributed Systems | Rate Limiting | IP & Domain Reputation | Amazon SES | MTA | Kubernetes | Observability

📌 Email Infrastructure & Deliverability Engineer (India)
🏢 Tech Sierra
📍 India