Klaviyo is growing fast and we have openings for all skill levels across all of our teams. Learn more about our engineering culture at https://klaviyo.tech

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.

Lead Engineers are expected to bring to Klaviyo subject matter expertise and demonstrate adaptability by continuing to acquire and master new skills, level up all those around them, and research and prototype new technologies and solutions to help scale Klaviyos systems and product capabilities. Klaviyo operates a real-time data platform coded in Python built for massive scale on Amazon Web Services (AWS). Engineers come to Klaviyo with experience in a variety of languages and from a number of disciplines. All engineers are expected to become extremely proficient in the technologies we use (not exhaustive):

Python, Django, Java, Celery

MySQL, Cassandra, RabbitMQ, Redis

HTML, JavaScript, LESS, Backbone.js, React

Amazon Web Services (EC2, RDS, Aurora, etc.)

Terraform, Ansible, Packer, and other DevOps tools

How you will make a difference:

• Wholly owning features that thousands of our customers rely on daily to reach 100,000,000+ of consumers to drive their business forward.
• Working on crafting our highly scalable real-time data pipeline that processes billions of events weekly across data sets growing to petabyte scale.
• Working on deep analytics system that provides insight into hundreds of terabytes of data.
• Be responsible for the mission, technical direction and operations of projects that have immediate impact.
• Helping architect and design robust and high performance data processing and storage systems leveraging new databases to serve different internal and external use cases. Contribute to open source data processing technologies.
• Contributing to the company as a subject matter expert in multiple areas, constantly pushing yourself to be a better engineer and to level up all of your peers within your team and within Klaviyo.

Who you are:

• Have 5+ years of experience building products that matter and pushing yourself and your team to be better engineers and build a product with passionate advocates
• Enjoy working with new technologies ranging from the frontend to backend, and are particularly passionate and an expert in multiple stack areas. You show this by having strong and opinionated experience with various technologies and know how to pick the right tool for any job
• Love digging into performance and scalability issues to drive breakthrough solutions-- whether it's a slow loading UI or too many clicks in a workflow, a database query timing out, or a queue that just wont drain. You recognize all problems can be solved
• Enjoy shipping code early & often in an agile fashion, pairing with product management to craft better software by soliciting feedback from thousands of end users
• Like working on 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 worlds 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 doesnt force companies to compromise between advanced functionality or ease of use - so companies of all sizes are able to maximize their sales quickly. Thats why over 28,000+ innovative companies like Unilever, Custom Ink and Eventbrite sell more with Klaviyo.