Senior Software Engineer, Backend

customerio; United States; Remote; USD 150,000 - 200,000; Full time

Benefits offered by this job

Unlimited PTO

16 weeks parental leave

Remote work stipend

Professional development budget

Remote hiring process

Job summary

Customer.io is seeking a senior backend engineer to architect and evolve distributed systems behind a high-scale messaging platform delivering emails, push notifications, in-app messages, and SMS to billions. The role emphasizes reliability, performance, and ownership from design through deployment.

You will build Go services, own end-to-end decisions, and collaborate across teams to ensure scalable, observable production systems. A strong product focus and leadership in initiatives are valued.

Qualifications

• Seven or more years of experience building scalable, distributed systems
• Go or comparable statically typed language experience
• Experience in cloud-native environments (AWS or GCP)
• Familiarity with relational databases (MySQL)
• Hands-on observability tooling and operating production systems at scale
• Bias for action and ownership of significant technical decisions
• Product-oriented mindset delivering real user value

Responsibilities

• Design, build, and operate distributed services in Go powering large-scale message delivery
• Own end-to-end architecture, schema design, testing, deployment, and monitoring
• Collaborate across teams to debug production issues and deliver reliable solutions
• Participate in on-call rotation to support system reliability
• Mentor peers and raise engineering standards through knowledge sharing and writing
• Leverage AI-assisted tooling to scope and verify multi-file code changes

Job description

Role overview

A senior backend engineering position focused on building and evolving the distributed systems behind a large-scale messaging platform that delivers emails, push notifications, in-app messages, and SMS to billions of recipients. The role centers on reliability, performance, and scalability, with engineers expected to take ownership from architecture through deployment and to shape how the team approaches complex problems.

Responsibilities

• Design, build, and operate distributed services in Go that power timely, relevant message delivery at scale
• Own problems end to end, including architecture, schema design, testing, deployment, and monitoring
• Collaborate across teams to debug production issues and deliver dependable solutions
• Participate in an on-call rotation to support the reliability of systems you help build
• Mentor peers and raise the engineering bar through knowledge sharing, writing, and short technical videos
• Use AI-assisted tooling to scope and verify multi-file code changes

Requirements

• Seven or more years of experience building scalable, distributed systems in Go or a comparable statically typed language
• Comfort working in cloud-native environments such as AWS or GCP
• Familiarity with relational databases (MySQL experience) and an understanding of performance tradeoffs
• Hands-on experience with observability tooling and operating production systems at scale
• A bias for action over perfection, with confidence owning significant technical decisions
• Product-oriented mindset, treating systems as a means to deliver real user value

Nice to have

• Prior leadership of complex initiatives, formally or informally
• Experience applying AI agents to day-to-day engineering workflows
• Background in behavioral-data-driven messaging or automation platforms

Benefits and work setup

• Starting salary of $150,000-$200,000 USD (or local-currency equivalent), depending on experience
• 100% coverage of medical, dental, vision, mental health, and supplemental insurance premiums for employees and their families
• 16 weeks of paid parental leave and unlimited PTO
• Stipends for remote work and wellness, plus a professional development budget
• Fully remote hiring process with structured steps: application review, recruiter call, hiring manager interview with a short AI-assisted coding exercise, collaborative system-design interview, take-home assignment, and assignment review