Senior Software Engineer - Email Channel

Stack

Responsibilities

• ▹Build frontend experiences customers use to create, preview and analyze email campaigns (template editors, sending configuration, deliverability dashboards)
• ▹Design and scale backend systems powering high-volume email sending (queue management, retry logic, event processing for bounces, complaints, deferrals)
• ▹Own deliverability-adjacent systems: bounce classification, suppression management, IP/domain reputation monitoring, feedback loop processing
• ▹Partner with the deliverability team to turn domain expertise into automated tooling (reputation scoring, warm-up schedules, sending throttles)
• ▹Instrument and monitor the health of the email channel (inbox placement signals, block detection, ESP feedback, alerting)
• ▹Own problems end to end — architecture, schema design, testing, deployment, monitoring
• ▹Share knowledge through videos, writing and mentorship
• ▹Use AI agents to make multi-file changes

Requirements

• ▹7+ years building scalable, distributed systems in Go (or similar statically typed languages)
• ▹Experience building product-facing frontend features in React or similar, with attention to UX quality
• ▹Comfort in cloud-native environments (AWS, GCP)
• ▹Familiarity with relational databases (primarily MySQL) and performance tradeoffs
• ▹Familiarity with high-volume email sending concepts: bounce handling, feedback loops, delivery event processing
• ▹Working knowledge of email authentication standards (SPF, DKIM, DMARC)
• ▹Comfort reasoning about sender reputation, IP warm-up and ISP behavior at scale
• ▹Experience with observability tooling and operating production systems
• ▹Experience building or consuming APIs handling high-throughput async workloads

Soft skills

What we offer

• ▹Starting salary $150,000-$200,000 USD, depending on experience
• ▹100% coverage of medical, dental, vision, mental health and supplemental insurance
• ▹16 weeks paid parental leave
• ▹Unlimited PTO
• ▹Remote work and wellness stipends, professional development budget

About the company

Over 8,000 companies — from scrappy startups to global brands — use Customer.io's platform to send billions of emails, push notifications, in-app messages and SMS every day. Under the hood: Go, React, Ember and AI help ship fast and scale reliably.