Senior Backend Engineer, Activation and Engagement Server (Growth)

Since we opened our doors in 2009 the world of commerce has evolved immensely and so has Square. After enabling anyone to take payments and never miss a sale we saw sellers stymied by disparate outmoded products and tools that wouldnt work together.

So we expanded into software and started building integrated omnichannel solutions to help sellers sell online manage inventory offer buy now pay later functionality book appointments engage loyal buyers and hire and pay staff. Across it all weve embedded financial services tools at the point of sale so merchants can access a business loan and manage their cash flow in one place. Afterpay furthers our goal to provide omnichannel tools that unlock meaningful value and growth enabling sellers to capture the next generation shopper increase order sizes and compete at a larger scale.

Today we are a partner to sellers of all sizes large enterprise-scale businesses with complex operations sellers just starting as well as merchants who began selling with Square and have grown larger over time. As our sellers grow so do our solutions. There is a massive opportunity in front of us. Were building a significant meaningful and lasting business and we are helping sellers worldwide do the same.

The Role

The Activation and Engagement Server Team is a critical part of Squares Growth Product organization with a mission to help more sellers use Square more. As part of the Growth Product teams strategy to Simplify Automate and Graduate seller experiences we build and maintain the backend infrastructure that guides sellers from signup through their first payment and beyond into ongoing product engagement. Were directly contributing to Squares growth initiatives focused on increasing new volume and seller success. Our primary goal is to improve onboarding and engagement for Square sellers while maintaining the reliability uptime and scalability of critical backend services powering onboarding flows.

Were addressing significant opportunities in the seller onboarding journey by building robust extensible APIs that enable web onboarding point of sale and international teams to deliver seamless activation experiences that convert and engage sellers at scale. Our work spans the entire seller journey from acquisition through activation and engagement focusing on automating complex workflows and removing friction from critical seller moments.

Were looking for a Senior Backend Engineer to help us scale our platform lead technical initiatives and mentor the next generation of engineers as we accelerate Squares growth.

You Will

• Drive onboarding and engagement improvements by designing and building highly available backend services that power critical seller experiences including setup guides onboarding checklists automated workflows and engagement features
• Build scalable distributed systems to handle millions of seller interactions across web mobile and international platforms while maintaining high reliability SLOs
• Lead cross-team technical initiatives spanning multiple engineering organizations coordinating architecture decisions to support Growth Products strategy of simplification and automation
• Own the full feature lifecycle from requirements analysis through API design implementation testing deployment monitoring and production support with direct impact on growth metrics
• Mentor and guide engineers across the team and broader organization through code reviews technical discussions and knowledge sharing
• Act as a technical leader for ambiguous complex projects that require coordinating multiple stakeholders and driving to resolution
• Enable extensibility and automation by building systems that outside engineers can easily understand diagnose and extend supporting Growth Products principles of rapid iteration and empowerment

You Have

• 8 years of hands-on experience building Java/Kotlin microservices and APIs at meaningful scale (exceptional candidates with less experience but proven track record will be considered)
• Strong expertise in distributed systems design and implementation including experience with event-driven architectures data consistency workflow orchestration and automation platforms
• Strong API design skills for both internal and external consumption (REST/gRPC) with focus on reliability extensibility and supporting high-conversion user experiences
• Production ownership experience including incident response SLO management and operational excellence in high-traffic environments
• Technical leadership track record on multi-person cross-team projects with demonstrated ability to mentor and guide other engineers
• Growth mindset and bias toward action with accountability for business outcomes and passion for moving fast while maintaining quality
• Excellent communication and collaboration skills with proven ability to influence teams beyond your immediate scope and work effectively in a fast-paced outcome-driven environment
• Experience with modern cloud infrastructure (AWS Kubernetes containerization) and CI/CD practices

Preferred Qualifications:

• Experience in growth engineering conversion optimization or funnel analysis
• Background with payments onboarding/activation user engagement or fintech domains
• Experience building automation platforms or workflow orchestration systems
• Knowledge of A/B testing frameworks and experimentation platforms
• Background with high-scale consumer or B2B SaaS products focused on user activation and retention

Technologies We Use and Teach

• Languages: Java(primary) Kotlin
• APIs & Communication: gRPC REST Protocol Buffers
• Frameworks: Guice Hibernate
• Experimentation: Optimizely LaunchDarkly.
• Testing: JUnit Mockito integration testing frameworks

Were working to build a more inclusive economy where our customers have equal access to opportunity and we strive to live by these same values in building our workplace. Block is an equal opportunity employer evaluating all employees and job applicants without regard to identity or any legally protected class. We will consider qualified applicants with arrest or conviction records for employment in accordance with state and local laws and fair chance ordinances.

We believe in being fair and are committed to an inclusive interview experience including providing reasonable accommodations to disabled applicants throughout the recruitment process. We encourage applicants to share any needed accommodations with their recruiter who will treat these requests as confidentially as possible. Want to learn more about what were doing to build a workplace that is fair and square Check out our ID page.

While there is no specific deadline to apply for this role U.S. roles are typically open for an average of 55 days before being filled by a successful candidate. Please refer to the date listed at the top of this job page for when this role was first posted.