Senior Site Reliability Engineer

Over 7,500 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 a Site Reliability Engineer to help us scale our infrastructure, reduce operational toil, and increase reliability as we grow. If you’ve worked on high-scale systems and love making platforms better for developers and customers alike, we’d love to meet you.

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

You think like a user, not just an engineer. You think about performance, reliability, and how systems impact the customer experience.

A healthy skepticism for “the way things are done”
You bring rigor and creativity. Best practices matter - but never more than forward motion.

• Build and scale infrastructure to support billions of messages per day and real-time events
• Automate deployments, alerting, and incident response
• Make our on-call better - clear alerts, solid documentation, and faster resolution
• Tune MySQL and other datastore performance and improve reliability across distributed systems
• Collaborate across teams to debug, ship, and support systems in production
• Share knowledge and raise the bar through sharing your progress publicly with short videos, thoughtful writing, and mentorship
• Leverage AI tools to prototype, move faster, and make better decisions

• 7+ years in SRE or infrastructure roles, improving production systems at scale
• Deep MySQL experience - schema design, performance tuning, and operational tooling
• Fluency in cloud-native tech (GCP a plus) and Terraform
• Proficiency in Go and Bash for scripting and systems programming
• Skill in observability, incident response, and debugging distributed systems
• A preference for action over perfection, and pride in owning technical decisions

We believe in transparency. Starting salary for this role is $140,000 - $180,000 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. Our inclusive benefits package supports your well-being and growth, including 100% coverage of medical, dental, vision, mental health, and supplemental insurance premiums for you and your family. We also offer 16 weeks paid parental leave, unlimited PTO, stipends for remote work and wellness, a professional development budget, and more.

See full benefits here →

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.
• Behavioral Interview (60 mins) - Talk with one of our hiring managers. We’ll explore topics like ownership, product thinking, and collaboration.
• Take-Home Assignment - Complete a short, realistic task similar to what you’d work on here.
• Technical Interview + Assignment Review Call (90 mins) - Walk us through your take-home project and the decisions you made along the way. We’ll also collaborate on a system design problem, focusing on real-world scaling challenges and tradeoffs.

All final candidates will be asked to complete a background check and employment verifications as part of our pre-employment process.

Customer.io recognizes the stifling impact of systemic injustice on diverse communities. We commit to using our influence to increase inclusion and equity within the tech industry. We strive to build an inclusive team culture, implement bias-free hiring practices, and develop community partnerships to expand our global impact.

Zoom is the only video conference platform that we use, virtual interviews will be conducted using the video capability (i.e., not via the chat), and offers will be extended in writing on official Customer.io letterhead. Please be vigilant in all of your job search activity, and if you have any questions please contact [email protected].

We believe in empathy, transparency, responsibility, and, yes, a little awkwardness. If you’re excited by what you read and want to build software that makes communication better for everyone—apply now.