Senior Software Engineer - K Agent

At Klaviyo, we value the unique backgrounds, experiences and perspectives each Klaviyo (we call ourselves Klaviyos) brings to our workplace each and every day. We believe everyone deserves a fair shot at success and appreciate the experiences each person brings beyond the traditional job requirements. If you're a close but not exact match with the description, we hope you'll still consider applying. Want to learn more about life at Klaviyo? Visit careers.klaviyo.com to see how we empower creators to own their own destiny.
Location: Boston Hybrid (3 days/week in office)
Why You Should Join the K Agent Team:
The K Agent team is building intelligent AI agent solutions that help brands scale personalized experiences and automate workflows. Our solutions will power thousands of brands and millions of users, embedding intelligent assistants into customer experiences in spaces like e-commerce. We're tackling challenging backend scaling, agent architecture, and semantic retrieval problems at web scale - all in service of helping our customers deliver improved interactions and experiences for their customers.
As a Senior Software Engineer on this team, you'll play a key role in designing and building scalable backend systems that power our AI agent solutions. You'll partner closely with product managers, data scientists, and fellow engineers to scale our systems substantially by year-end - driving real-world impact at scale. This is a backend-heavy role with opportunities to influence architecture, async processing pipelines, distributed systems, and more.
How You Will Make a Difference:

• Design and build backend systems that support scaling our AI solutions from dozens to thousands of brands.
• Develop robust asynchronous processing pipelines that gather and index contextual data from the internet.
• Contribute to evolving our agentic architecture - making our AI agents more self-sufficient and performant.
• Collaborate with teammates to build and optimize semantic retrieval solutions.
• Help scale our platform to support web-scale user interactions - embedded in platforms like Shopify with tens of thousands of users.
• Contribute to a culture of ownership, experimentation, and customer-centric product thinking.

Who You Are:

• Experienced backend engineer with a strong track record of building scalable, distributed systems.
• Proficient in Python and modern backend frameworks (FastAPI, Django preferred).
• Deep experience with asynchronous processing and distributed task queues (Celery, Kafka, SQS, RabbitMQ, Redis).
• Strong understanding of database technologies and ORMs (SQLAlchemy, Alembic).
• Comfortable with cloud-native architectures (AWS) and container orchestration (Kubernetes); can manage infrastructure and CI/CD pipelines.
• Skilled at designing and building robust APIs.
• Familiar with search engine technologies and semantic retrieval (Elasticsearch or similar) - nice to have but not required.
• Able to operate with a high degree of autonomy, handle ambiguity, and thrive in a fast-moving, startup-like environment.
• Comfortable collaborating directly with product and customers to shape solutions.

Technologies We Use (Not Exhaustive):

• Languages & Frameworks: Python, Django, FastAPI, React, Typescript
• Databases & ORMs: SQLAlchemy, Alembic
• Queues & Processing: Kafka, SQS, Redis, Celery
• Cloud & Infra: AWS, Kubernetes, Terraform

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
Massachusetts Applicants:It is unlawful in Massachusetts to require or administer a lie detector test as a condition of employment or continued employment. An employer who violates this law shall be subject to criminal penalties and civil liability.
Our salary range reflects the cost of labor across various U.S. geographic markets. The range displayed below reflects the minimum and maximum target salaries for the position across all our US locations. The base salary offered for this position is determined by several factors, including the applicant's job-related skills, relevant experience, education or training, and work location.
In addition to base salary, our total compensation package may include participation in the company's annual cash bonus plan, variable compensation (OTE) for sales and customer success roles, equity, sign-on payments, and a comprehensive range of health, welfare, and wellbeing benefits based on eligibility. Please visit Klaviyo Rewards to find out more about our Total Rewards package.
Your recruiter can provide more details about the specific salary/OTE range for your preferred location during the hiring process.
Base Pay Range For US Locations:
$152,000 - $228,000 USD
Get to Know Klaviyo
We're Klaviyo (pronounced clay-vee-oh). We empower creators to own their destiny by making first-party data accessible and actionable like never before. We see limitless potential for the technology we're developing to nurture personalized experiences in ecommerce and beyond. To reach our goals, we need our own crew of remarkable creators-ambitious and collaborative teammates who stay focused on our north star: delighting our customers. If you're ready to do the best work of your career, where you'll be welcomed as your whole self from day one and supported with generous benefits, we hope you'll join us.
Klaviyo is committed to a policy of equal opportunity and non-discrimination. We do not discriminate on the basis of race, ethnicity, citizenship, national origin, color, religion or religious creed, age, sex (including pregnancy), gender identity, sexual orientation, physical or mental disability, veteran or active military status, marital status, criminal record, genetics, retaliation, sexual harassment or any other characteristic protected by applicable law.
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