Staff Software Engineer, Backend

Details

Customer.io is looking for a staff engineer to set technical direction for systems that move billions of messages per day. The role focuses on architectural decision-making, solving high-stakes cross-functional problems, and raising the effectiveness of engineers across the department.

Customer.io's platform helps more than 9,000 companies send emails, push notifications, in-app messages, and SMS using real-time behavioral data. The technology stack includes Go, React, Ember, and AI.

Responsibilities

• Shape the technical direction of distributed messaging systems in Go, making high-level architectural decisions for mission-critical services where scale, cost, and reliability are in tension.
• Solve ambiguous, high-stakes problems that cross squad and function boundaries, driving them to decisions when the right answer is not obvious.
• Build consensus on contested technical questions across teams and communicate trade-offs clearly to senior leadership.
• Set quality and design standards, mentor senior engineers, and create frameworks and documentation that enable other teams to work independently.
• Drive engineering process and tooling improvements across multiple squads.
• Interview candidates and calibrate assessments against the company's career ladder.
• Use AI agents to make multi-file changes by scoping work, writing prompts, and verifying outputs.

Requirements

• 10+ years of experience building scalable, distributed systems in Go or similar statically typed languages, including several years as an architectural resource for other engineers.
• Demonstrated depth across multiple systems or domains.
• Experience designing for production realities and quantifying trade-offs involving throughput, cost, and reliability.
• Experience treating observability and recovery as first-class concerns, including metrics, alerting, rollback, backpressure, and checkpointing.
• Comfort working in cloud-native environments such as AWS and GCP.
• Experience with relational databases; Customer.io uses MySQL.
• Strong understanding of performance trade-offs.
• Evidence of improving other engineers through mentorship, technical writing, design reviews, or standards that continued to provide value after involvement ended.
• A bias for action and the judgment to identify decisions that warrant additional consideration.

Compensation And Benefits

• Starting salary: $200,000–$240,000 USD, or equivalent in local currency, depending on experience and subject to market rate adjustment.
• 10% annual bonus target.
• 100% coverage of medical, dental, vision, mental health, and supplemental insurance premiums for employees and their families.
• 16 weeks of paid parental leave.
• Unlimited paid time off.
• Remote work and wellness stipends.
• Professional development budget.

Hiring Process

1. Application review.
2. A 30-minute recruiter call.
3. A 60-minute hiring manager interview covering working style, an end-to-end project, and a short AI-assisted coding exercise.
4. A 60-minute architecture interview focused on scaling challenges, trade-offs, and failure modes.
5. A short take-home assignment based on a realistic work task.
6. A 60-minute assignment review call covering the candidate's work, trade-offs, priorities, and iteration approach.

Final candidates must complete a background check and employment verifications. Virtual interviews are conducted using Zoom. Offers are extended in writing on official Customer.io letterhead.