Software Engineer II (Mobile Developer - Android/Kotlin) - Mobile App Growth

Why you should join the Mobile App Growth team

The Mobile App Growth team's mission is to enable Klaviyo customers to develop and maintain personalized relationships with their mobile app users through rich mobile app experiences. The team is part of the Mobile App Marketing org and owns Klaviyo's mobile SDKs — the foundational layer that enables customers to integrate Klaviyo into their mobile apps. We maintain native and wrapper SDKs across iOS, Android, React Native, Expo, and Flutter.

As a natural extension of the SDK, the team also builds and maintains adjacent mobile products that are enabled by it:

• In-app messaging — including the in-app messaging publishing and scheduling pipeline 
• Universal linking — universal links settings pages and web tier 
• Geofencing

That product list keeps expanding — this year alone the team is greenfielding several new features, including mobile inbox. We're looking for passionate engineers who want to roll up their sleeves and grow beyond just Android into the other areas the team owns.

How you'll make an impact

• Design, build, and ship features and fixes to the Android SDK — your primary area of ownership — used across a huge range of third-party apps and OS versions/devices.
• Pitch in on our other mobile SDKs (iOS, React Native, Expo, and Flutter) when priorities call for it; you don't need to be an expert everywhere, but you should be willing to get hands-on.
• Contribute to the backend services, infrastructure, and embedded web UI that power products like in-app messaging, universal linking, and geofencing — including newer greenfield work like mobile inbox.
• Diagnose and resolve SDK issues reported by customers.
• Write clean, well-tested code and participate in code and design review.
• Collaborate with product and other engineering teams to keep tracking and messaging behavior consistent across platforms.
• Contribute to documentation, sample apps, and integration guides that customers use to adopt the SDKs.

Who you are

• Android-first — 1-3 years of professional Android development experience, ideally including Kotlin; this is your core strength and primary focus.
• Self-motivated — you don't need heavy oversight to make progress; you take a problem, figure out the right questions, and drive it to done.
• High ownership — you treat outcomes as yours end-to-end, not just the code you personally typed. As AI tooling raises how much one engineer can credibly own, this matters more than it used to.
• Adaptable — willing to pick up iOS, backend, or frontend work when it falls under the team's ownership; you don't need to be an expert everywhere.
• Production-tested — experience shipping and maintaining production Android code, with a solid grasp of the Android lifecycle, threading, and Gradle.
• Comfortable in the weeds — used to debugging across a wide matrix of devices, OS versions, and third-party app environments, since SDK work means you don't control the host app.
• Quality-minded — familiar with testing practices (unit, integration, instrumentation) and CI/CD for mobile.
• Clear communicator — you'll work with customers' engineering teams as well as your own.
• Curious — comfortable with webviews and location services, and open to picking up new technologies (Python, React, AWS) as the team's surface area grows.
• Bonus: experience building or maintaining an SDK/library (versus an app), exposure to iOS/Swift or backend services, familiarity with push notification/messaging systems, or contributions to open source.

Technologies We Use (not exhaustive)

• iOS (Swift)
• Android (Kotlin)
• React Native
• Flutter
• React, TypeScript, Redux
• Python, Django
• MySQL, Redis, DynamoDB
• AWS (EC2, RDS, Aurora), Terraform

***This is an in-office position and the expectation is to work from the Boston office five (5) days per week***