Lead AI Engineer, Klaviyo
£140k
3+ days a week in office
The B2C CRM
Be an early applicant
£140k
3+ days a week in office
1001+ employees
Company mission
Klaviyo is the only CRM built for B2C brands. Powered by its built-in data platform and AI insights, Klaviyo combines marketing automation, analytics, and customer service into one unified solution, making it easy for businesses to know their customers and grow faster.
Role
Who you are
- 7–10 years of professional software engineering experience, with a strong focus on backend systems and distributed architectures
- Recent, hands-on experience with AI/ML and LLMs, including fine-tuning, evaluation, and production deployment
- Proven ability to design and scale distributed systems that support AI-driven applications and agent capabilities
- Proficient in Python and modern backend frameworks (FastAPI, Django preferred)
- Skilled with big data tools (Apache Spark, Hadoop) and distributed task queues (Kafka, Celery, SQS, RabbitMQ, Redis)
- Experienced in architecting APIs and cloud-native solutions (AWS, Kubernetes, CI/CD pipelines)
- Demonstrated technical leadership — mentoring engineers, shaping architecture, and raising the bar for engineering practices
- Thrives in a fast-paced, startup-like environment with high autonomy and ownership
- Curious, adaptable, and motivated to stay on the cutting edge of AI/ML research and apply it to real-world business challenges
Desirable
- Experience training and deploying reinforcement learning systems
- Prior experience leading cross-functional initiatives involving data science, ML engineering, and product
What the job involves
- As a Lead Software AI Engineer at Klaviyo, you’ll set technical direction and drive the design of scalable backend systems and AI-powered user experiences that form the foundation of our AI product strategy
- You’ll work closely with product managers, machine learning engineers, and data scientists while mentoring engineers and shaping architectural decisions
- This is a backend-heavy leadership role with a strong focus on applied AI/ML, including large language models (LLMs) and agentic AI systems
- Lead the design and development of backend systems that enable scalable AI solutions for 167K+ customers
- Architect robust, reliable, and scalable data pipelines that train and serve AI/ML models at scale
- Drive the integration of LLMs into production systems, powering AI agents that create and execute real-time customer experiences
- Establish best practices for model evaluation, monitoring, and performance across generative and agentic AI use cases
- Mentor and guide engineers, fostering a culture of technical excellence, ownership, and customer-centric product thinking
- Partner with cross-functional leaders to influence AI product strategy and deliver high-impact solutions
Application process
- We use Covey as part of our hiring and / or promotional process. As part of the evaluation process we provide Covey with job requirements and candidate submitted applications
Salary benchmarks
Our take
Klaviyo is a marketing firm helping growth-focused eCommerce brands drive more sales with super-targeted, highly relevant email, Facebook and Instagram marketing campaigns. From personalised newsletters to automated emails when customers abandon their shopping carts, the marketing automation platform makes it easy for businesses to capture, store, analyze, and predictively use their own data to drive measurable, high-value outcomes.
Klaviyo's CEO, Bialecki, believes that the main problem with e-mail marketing today is that there is a divide between two kinds of tools: analytics tools that help you understand what people are doing on a website, such as what products they are considering, and messaging tools that send them a marketing e-mail. Operating primarily within the retail and eCommerce industry, Klaviyo aims to solve this by offering a tool that brings together analytics and messaging. This allows companies to bring all of their first-party data into a single platform to get a deep understanding of their customers and then activate that data to deliver highly-targeted, personalised communications through email and SMS. In the process, Klaviyo's customers get a deep understanding of their consumers.
Klaviyo is a fast-growing company mainly due to its business model - the firm offers a concrete ROI for Klaviyo’s clients if the software persuades customers to make purchases by treating different types of customers differently. An IPO in 2023 has led to Klaviyo's release of Klaviyo AI, which empowers businesses to unlock revenue-driving opportunities and deliver exceptional customer experiences across channels. Still in its early days of public listing, it will be interesting to see how Klaviyo fares in the years to come.
Freddie
Company Specialist at Welcome to the Jungle
Meet the team
2 people
Blake Schuller, Manager of New Hire Onboarding
Our mission
Base Camp provides a best in class onboarding program, fueled by 'just in time' learning throughout a new hires' first 100 days.Insights
Company
Employee endorsements
Opportunities to learn
"Not only we have a good stipend to spend on learning but we also have development days every quarter, where we can switch off and focus on the areas..."
Company benefits
- Private medical insurance
- Medical
- Dental
- Vision
- Lifestyle spending account
- Commuter benefits
- Modern Health - wellness platform
- Parental leave
- Company equity
- Employee stock purchase plan
- Private medical insurance through Vitality
- Private medical insurance through Bupa
- Vision - expense one eye test per year, and up to £50 per year towards glasses.
- Pension
- Financial coaching
- Life insurance
- Income protection
- Annual leave - up to 28 annual leave days
- 10 company holidays
- Family leave
- Cycle to Work benefit
Company values
- Put customers first: We prioritize our customers > customers’ customers > team > ourselves. We empathize deeply with our customers by walking in their shoes and solving their greatest pain points. We start with what’s best for the customer, not what’s best for us, and work backwards, delivering experiences our customers will talk about.
- Win together: We’re one team, we get to know each other, we’re okay with conflict and willing to disagree and commit. We are honest, direct, transparent, and respectful. We seek and incorporate diverse perspectives and assume good intent.
- We’re 1% done: We’re just getting started – our greatest products, work, and achievements are in front of us. We have a beginner’s mindset – we see the opportunities to build and improve and have the ambition to go after them. We benchmark against the best, aim to beat them, and celebrate when we do.
- Know the score: We’re clear about what success is for each project and how it ladders to our overall success. Results are what matter. Working hard is required, but it’s not success. We use data and past performance to motivate our future strategy.
- Be meticulous in your craft: We seek to do work so good that people rave about it. We are rigorous, thorough and prepared. We are or expect to be the experts everyone in the world turns to.
- Move fast, no shortcuts: Speed matters. We set ambitious deadlines, we like short cycles and being first to market. We don’t skip critical steps or requirements to make a date. We’re comfortable living in the grey and making judgment calls to decide what’s required and what’s not.
- Drivers wanted: No passengers — we’re proactive and engaged, and if we see something wrong it’s our responsibility to fix it or raise the issue to its owner. Have a vision and make sure it’s compelling. No job is beneath us. If it needs to get done, we’re happy to pick it up. We use and spend resources like they’re our own.
- Stay hungry, stay humble: We are insatiably curious learners; our slopes are very high. If we don’t know something, we’re world- class at figuring it out. We take calculated risks and sometimes make mistakes — we’re not perfect. When we fail, we learn from it and improve going forward. Feedback is a gift, even if it hurts sometimes. We don’t tolerate brilliant jerks.
Company HQ
Boston, MA
Articles
Leadership
Andrew Bialecki
(CEO)Previously CTO at RockTech, Senior Engineer at Performable, Lead Engineer at Applied Predictive Technologies and an SDET Intern at Microsoft
Ed Hallen
(Chief Product Officer)Currently an Advisor at Team Engine. Previously worked in Enterprise Business Development at Google, Summer Associate at Accel-KKR and Principal at Applied Predictive Technologies.
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