Senior Software Engineer - Email Channel

Americas, United StatesRemote

Responsibilities

Build and evolve the frontend experiences customers use to create, preview, and analyze email campaigns — template editors, sending configuration, deliverability dashboards
Design and scale the backend systems that power high-volume email sending, including queue management, retry logic, and event processing (bounces, complaints, deferrals)
Own deliverability-adjacent systems: bounce classification, suppression management, IP/domain reputation monitoring, and feedback loop processing
Instrument and monitor the health of the email channel: inbox placement signals, block detection, ESP feedback, and alerting
Own problems end to end — from architecture and schema design to testing, deployment, and monitoring

Customer.io powers automated communication that people actually want to receive.
We help teams send smarter, more relevant messages using real-time behavioral data. Under the hood: Go, React, Ember and AI help us ship fast and scale with confidence. What We Value Ownership
Use AI agents to make multi-file changes by scoping the work, writing the prompt, and verifying the output What We're Looking For 7+ years of
experience building scalable, distributed systems in Go (or similar statically typed languages) •
Experience building product-facing frontend features in React or similar frameworks, with attention to UX quality and polish
Comfort working in cloud-native environments (AWS, GCP)
Familiarity with relational databases (we use MySQL primarily) and an understanding of performance tradeoffs
Familiarity with high-volume email sending concepts: bounce handling, feedback loops, and delivery event processing
Working knowledge of email authentication standards — SPF, DKIM, DMARC — and how they affect deliverability
Experience with observability tooling and operating production systems •
Experience building or consuming APIs that handle high-throughput async workloads