Software Engineer II Custom Objects
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Job Location:
Boston, NH - USA
Monthly Salary:
Not Disclosed
Posted on:
11 hours ago
Vacancies:
1 Vacancy
Job Summary
Software Engineer II Custom Objects Platform
Background
Klaviyo operates a real-time data platform built for massive scale powering segmentation automation analytics and personalization for hundreds of thousands of customers. At the core of this platform are three foundational data entities: Profiles Events and Objects.
The Custom Objects team owns the platform that allows customers to define store and evolve their own domain-specific data models enabling richer personalization advanced segmentation and flexible analytics beyond Klaviyos built-in data types.
As a Software Engineer II on the Custom Objects team youll help build and scale the systems that allow customers to safely model query and activate their custom data at scale.
How Youll Make an Impact
Custom Objects unlock how customers represent their business inside Klaviyo.
In this role youll:
- Build systems that support customer-defined schemas and flexible data models
- Enable other teams (Flows Segmentation Analytics AI) to safely rely on object data
- Work on platform primitives that must balance flexibility correctness performance and cost
- Contribute to a core data surface that directly impacts customer experience and product velocity
What You Will Do
- Design build and maintain services that power the Custom Objects platform
- Implement APIs and data pipelines for creating updating and querying custom object data
- Work with evolving schemas while maintaining backwards compatibility and data integrity
- Collaborate with Product Events Profiles and Analytics teams to integrate custom objects into the broader platform
- Debug and improve performance of data-heavy systems operating at scale
- Participate in code reviews design discussions and on-call rotations
- Contribute to improving operational excellence through better observability and tooling
What Were Looking For
Required Qualifications
- 36 years of professional software engineering experience
- Experience building backend systems in a production environment
- Strong fundamentals in data structures algorithms and system design
- Experience working with databases or data storage systems (relational or distributed)
- Ability to reason about correctness tradeoffs and edge cases in stateful systems
- Strong communication skills and comfort working with cross-functional partners
Nice to Have
- Experience with schema-driven or user-defined data models
- Familiarity with distributed systems and high-throughput services
- Experience working with Python or similar backend languages
- Exposure to cloud infrastructure (AWS preferred)
- Experience supporting both online and analytical workloads
What Success Looks Like
In the First 90 Days
- Develop a strong understanding of Klaviyos data model and platform architecture
- Contribute meaningful code to production systems
- Learn how custom objects interact with Events Profiles and downstream consumers
- Participate effectively in design and code reviews
Over the First Year
- Own medium-sized features or system improvements end-to-end
- Improve reliability performance or usability of the Custom Objects platform
- Demonstrate strong judgment around data modeling and tradeoffs
- Be a reliable on-call contributor and teammate
- Help raise the overall engineering bar through thoughtful reviews and collaboration
Why This Role Is Unique
- Youll work on customer-defined data one of the hardest classes of platform problems
- Youll solve challenges around schema evolution correctness and scale
- Your work will directly impact how customers model their business and activate their data
- Youll gain deep experience in platform engineering at the heart of Klaviyos data systems
We use Covey as part of our hiring and / or promotional process. For jobs or candidates in NYC certain features may qualify it as an AEDT. As part of the evaluation process we provide Covey with job requirements and candidate submitted applications. We began using Covey Scout for Inbound on April 3 2025.
Please see the independent bias audit report covering our use of Covey here
Required Experience:
IC
Key Skills
- Spring
- .NET
- C/C++
- Go
- React
- OOP
- C#
- Data Structures
- JavaScript
- Software Development
- Java
- Distributed Systems
About Company
Klaviyo unifies AI-powered email marketing and SMS to drive growth, retention, and measurable results. Build personalized, omnichannel experiences across WhatsApp, ecommerce, and more with K:AI Agents.
