Senior Software Engineer - Backend Platform

Hi, I'm Manu, Engineering Manager at Customer.io . We're looking for experienced backend engineers who want to build and own the infrastructure that powers one of the most data-intensive platforms in marketing automation — systems that process millions of events per second, orchestrate complex workflows at scale, and keep everything running reliably for thousands of customers worldwide.

You'll work on the Platform team, tackling hard distributed systems problems: designing for fault tolerance, scaling services under real production pressure, and building the foundational layers that every other team at Customer.io depends on. This isn't just maintenance work — you'll shape the architecture of systems that need to be both highly available and constantly evolving.

If you're someone who gets energized by the intersection of scale, reliability, and developer experience — and wants ownership over infrastructure that truly matters — we'd love to talk.

What you'll bring:

Deep experience with distributed systems and large-scale backend architecture

Strong instincts around reliability, observability, and fault tolerance

Comfort reasoning about performance, capacity, and trade-offs at scale

Experience with event-driven systems, message queues, or data pipelines is a plus

A collaborative mindset — you raise the team around you

About Customer.io

Over 9,000 companies - from scrappy startups to global brands - use our platform to send billions of emails, push notifications, in-app messages, and SMS every day. 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

You drive technical direction across systems and teams. You move with urgency, build with empathy, and think long-term. You’ve led large-scale infrastructure initiatives and know what it takes to get them over the line.

Engineers with customer focus

You think about how infrastructure unlocks customer value. You care about developer experience, system design, and how your work shapes the customer experience.

A healthy disregard for “the way things are done”

You bring rigor and creativity. Best practices matter, but never more than forward motion.

What You’ll Do

Design and evolve distributed systems in Go to handle billions of daily events and messages and store and index petabytes of data

Lead architectural decisions around performance, reliability, and real-time event processing

Improve service-to-service communication through better APIs, messaging systems, and event-driven patterns

Work across teams to uncover bottlenecks and system issues, and lead initiatives to resolve them for a smoother customer experience