Senior Mobile Engineer

Boston, MA
Engineering – Mobile
Full Time
Klaviyo is growing fast and we have openings for all skill levels across all of our teams. Learn more about our engineering culture at

Klaviyo is looking for a Senior Mobile Software Engineer to drive our mobile initiatives. You will own Klaviyo’s mobile app utilized by our customers as well as the Android and iOS SDKs powering mobile analytics and engagement for many of today’s fastest-growing brands. 

Klaviyo builds SDKs in SwiftObjective-C for iOS and JavaKotlin for Android. In addition the mobile team plans to build two native mobile apps using Swift and Kotlin. This will also include building out the backend APIs to support features in these apps. Klaviyo’s platform is a real-time system built for massive scale on Amazon Web Services (AWS). Engineers come to Klaviyo with experience in a variety of languages and form a number of disciplines. The core Klaviyo platform is comprised of the following components and mobile engineers are expected to integrate with and learn a tremendous amount about the following tech:

HTML, JavaScript, React
Python, Django, Celery
MySQL, Cassandra, RabbitMQ, Redis, ElasticSearch Amazon Web Services (EC2, RDS, Aurora, EKS, etc...) 

We love tackling tough engineering problems and look for Engineers who specialize in certain areas but are passionate about building, owning & scaling features end to end from scratch and breaking through any obstacle or technical challenge in their way. We push each other to move out of our comfort zone, learn new technologies and work hard to ensure each day is better than the last.

How you will make a difference:

    • Build the official Klaviyo Native App for both iOS and Android to give Klaviyo customers key business insights when they need it.
    • Build SDKs for Android and iOS to enable brands to instrument and drive engagement and sales with their mobile apps.
    • Build new features with the team that built and maintains Klaviyo’s SMS and Push messaging platforms.
    • Help drive the mobile strategy of our customers by having direct customer conversations and ensuring the Klaviyo mobile roadmaps gives them what they need.
    • Have the chance to wholly own features that thousands of our customers rely on daily to reach 100,000,000+ of consumers to drive their business forward.
    • Advance your technical skills in all facets ranging from mobile engineering best practices, to full stack development and user experience to data science and leveraging massively parallelized data pipelines. You’re passionate about mobile but will have the opportunity to work on it all.
    • Contribute to the company as a subject matter expert in multiple areas, constantly pushing yourself to be a better engineer and to level up all your peers within your team and within Klaviyo. 

Who you are:

    • Have proven yourself building mobile apps that matter and pushing yourself to constantly write better code to build experiences that delight passionate users.
    • Possess a strong portfolio of mobile projects and web engineering projects. You’ve built multiple apps in many the chronologies over and are eager to share your learnings.
    • Stay on top of the latest mobile technologies, and are are particularly passionate and an expert in multiple mobile areas. You show this by having strong and opinionated experience with various technologies, know how to pick the right tool for any job, but understand that the mobile landscape is diverse and fragmented and you may be
    • expected to support other ecosystems.
    • Love digging into performance and scalability issues to drive breakthrough solutions — with it’s a slow starting app, too many taps in a workflow, or a feature timing out because a backend call is too slow. You recognize all problems can be solved.
    • Enjoy shipping code early and often in an agile fashion, pairing with product management to craft better software by soliciting feedback from thousands of end users.
    • Like working on a small, autonomous agile teams.
    • At Klaviyo, you will have ownership of features, but you’ll collaborate with everyone to make sure we produce the right solution. 
Get to know Klaviyo

Klaviyo is the world’s leading owned marketing platform known for accelerating revenue for online businesses using the channels they own like email, web, and mobile. Enabling companies to leverage these owned marketing channels, Klaviyo makes it easy to store, access, analyze and use transactional and behavioral data to power highly-targeted customer and prospect communications. And unlike other marketing platforms, Klaviyo doesn’t force companies to compromise between advanced functionality or ease of use - so companies of all sizes are able to maximize their sales quickly. That’s why over 28,000+ innovative companies like Unilever, Custom Ink and Eventbrite sell more with Klaviyo.