Customer.io

Senior Software Engineer - Email Channel

Americas Remote · Senior

Sponsorship not specified$150k-$200kDetected 67 days ago

ReactDistributed SystemsMySQLAWSGCPAgentic AIEmail MarketingCommunicationMentoring

About the role

Hi, I'm Brian, Senior Director of Engineering at Customer.io.
Customer.io powers automated communication that people actually want to receive.
We help teams send smarter, more relevant messages using real-time behavioral data.

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
Partner with our deliverability team to translate domain expertise into automated tooling - reputation scoring, warm-up schedules, sending throttles
Own problems end to end - from architecture and schema design to testing, deployment, and monitoring
Experience building product-facing frontend features in React or similar frameworks, with attention to UX quality and polish
Experience building or consuming APIs that handle high-throughput async workloads
Technical Interview (60 mins) - A collaborative system design conversation focused on scaling challenges.

7+ years of experience building scalable, distributed systems in Go (or similar statically typed languages)
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

We believe in transparency.
Starting salary for this role is $150,000 - $200,000 USD (or equivalent in local currency) depending on experience and subject to market rate adjustment.
We know our people are what make us great, and we're committed to taking great care of them.
No gotchas, no trick questions - just a clear, human process designed to help both of us make an informed decision.
Application - We review everyone with care. Tell us why you're interested.
Recruiter Call (30 mins) - Let's chat about what you're looking for and how we work.

Build and evolve the frontend experiences customers use to create, preview, and analyze email campaigns - template editors, sending configuration, deliverability dashboards
What We're Looking For
We're looking for experienced engineers who want to own the email channel end to end - from the infrastructure that delivers billions of messages reliably, to the product surfaces our customers use to build, send, and analyze their campaigns.

This listing is sourced directly from Customer.io's careers page and normalized into a canonical job model.