Senior Software Engineer, Backend

Over 8,000 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.

We’re looking for experienced backend engineers who care deeply about reliability, performance, and scalability. You’ll design, build, and evolve the systems that power communication at massive scale — while helping us push the boundaries of what great engineering can look like.

What We Value

Ownership : You own problems end to end. You move fast, act like an owner, and thrive in ambiguity. You've led complex projects before, whether officially or not, and you're ready to do it again.

Engineers with product taste : Yo...