Senior Software Engineer, Klaviyo
K Agent
$152-228k
3 days a week in office
The only CRM built for B2C
Posted today
$152-228k
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
- 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
What the job involves
- 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
- 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
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
Meet Blake, 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 health care cover
- All full time employees receive equity
- Commuting allowance for when you do travel to the office,
- A very generous education allowance every year for you to spend on learning and development.
- Participation in Klaviyo ESPP
- Personal lifestyle allowance
- Flexible holiday scheme
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
Dublin, Republic of Ireland
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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