Software Engineer, Full Stack (Senior, Staff+)

About Kustomer

Kustomer is the AI-native customer experience platform that turns every interaction into a lasting relationship and a measurable business outcome. By unifying customer data, conversations and AI-native workflows into a single connected timeline, Kustomer helps teams cultivate customers, not tickets, resolving issues faster and delivering more personalized service across every channel. Today, Kustomer is the core platform for leading customer service brands like Sweetgreen, Starz, Vuori, Goldbelly and Cotopaxi.

Founded in 2015 by serial entrepreneurs Brad Birnbaum and Jeremy Suriel, Kustomer raised nearly $200M in funding culminating in a Series E before being acquired by Meta in a deal that closed in 2022. In 2023, Kustomer's founders and original investors, Battery, Redpoint, and Boldstart Ventures, spun the company back out with a $60M investment as an independent, privately held business ready to focus more deeply on AI. In 2025, Norwest led our Series B, bringing our total funding to $90M. This momentum allowed Kustomer to double down on AI-native innovation and build a sharper roadmap for the future of customer experience. Our Krew is a remote-friendly team spread across the U.S. with hubs in NYC and London. We gather in person each year at our annual Kustomer Kick-Off event and always look for Krew members who are curious, collaborative, and ready to shape the future of Customer Experience.

About the Role

Kustomer is hiring a Full Stack Software Engineer to join our Engineering team. In this role, you'll work as part of a pod: a 3–5 person team that picks up a high-priority initiative, ramps quickly, ships end-to-end, and moves on to the next one. You'll be a capable, adaptable engineer who can walk into any part of the codebase, understand it, and make it better. You'll ship new capabilities, improve performance, and contribute to the evolution of our architecture using technologies like Node.js, React, Golang, and AWS, collaborating closely with your pod leader and teammates across engineering, product, and design.

AI is a core part of how we build. You'll use AI tools daily to move faster and raise the bar on what you ship. You'll also help build AI-powered product capabilities that meaningfully improve the customer experience.

We're looking for engineers with strong technical judgment, a high bar for craft, and real curiosity about how systems, product, and AI intersect. You take initiative, thrive in ambiguous problem spaces, and own your work end-to-end, from design through production. Not because someone's tracking it, but because you genuinely care about what you're building. If you want your work to directly shape the product and the team around you, we'd love to hear from you.

What You’ll Do:

• Ship full-stack features end-to-end as a member of a pod, owning scope from problem definition through production, using technologies like Node.js, React, Golang, MongoDB, ElasticSearch, and AWS

• Develop APIs and integrate with external services and databases, ensuring data integrity and security

• Build front-end interfaces with a focus on user experience, responsiveness, and accessibility

• Design and build AI-powered features that improve the user experience and platform efficiency

• Partner with PMs, engineers, and your Pod Lead to shape requirements, design, UX, and scope tradeoffs, communicating progress proactively along the way

• Optimize application performance through caching, efficient algorithms, and database indexing

• Write thorough unit and integration tests to ensure quality and reliability

• Conduct code reviews, provide constructive feedback, and mentor junior engineers to uphold a high quality bar

• Share production support responsibility on a rotating basis, including on-call and bug triage, distributed equitably across the team

• Stay current with emerging AI tools, full-stack technologies, and industry trends — and actively propose and champion those that improve team velocity, quality, and development practices

• Ramp quickly on unfamiliar parts of the codebase aided by AI tooling, consistent code hygiene, and a deep engineering foundation

Your qualifications:

• 7+ years of progressive software development experience and a Bachelor's degree in Computer Science, Software Engineering, or a related field

• You're comfortable working across frontend and backend. You may have a stronger side, and that's fine. What matters is that you can follow the work wherever it goes and aren't blocked by an unfamiliar layer.

• You understand how systems work at depth and have experience with cloud platforms like AWS or similar. Data structures, algorithms, concurrency, distributed systems, API design, database internals; these are tools, not trivia.

• You don't need to be the domain expert before contributing. You read READMEs, trace execution, ask sharp questions, and start adding value fast.

• You own the outcome, not just the ticket. You raise risks early, communicate progress proactively, and care about what ships, not just what you committed.

• You’re able to diagnose and debug complex issues, optimize application performance, and identify areas for improvement.

• You have hands-on experience with modern AI developer tools, such as Cursor or Claude Code, and have built a real working practice around using them as a force multiplier for code comprehension, test scaffolding, documentation, debugging, and ramp.

• Your application will stand out if you have:

  • Familiarity with integrating AI or ML-powered capabilities into web applications, even at a prototype or feature level

  • Exposure to integrating third-party AI APIs or frameworks (e.g., OpenAI, Anthropic, LangChain, or vector databases like Pinecone)

  • Interest in exploring how AI can enhance developer workflows and improve product functionality

  • Github activity showing thoughtful, relevant contributions

HIPAA Compliance

All roles at Kustomer may involve handling sensitive personal data.

Benefits

Kustomer offers an array of benefits including competitive salaries and stock options. In the U.S. we offer 100% healthcare coverage, 401K, WiFi and Mobile reimbursement, and a generous vacation policy; in the UK we also offer pension, supplemental health insurance and other perks.

Diversity & Inclusion at Kustomer

Kustomer is committed to bringing together individuals from different backgrounds and perspectives.

We strive to create an inclusive environment where everyone can thrive, feel a sense of belonging, and do great work together.We are proud to be an equal opportunity employer open to all qualified applicants regardless of race, color, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, disability, gender identity or expression, Veteran status, or any other legally protected status.

Candidate Privacy Notice

As a job applicant, you have the right to know and understand the categories of personal information we collect about you, and the purposes for which we use such personal information.

Disclaimer: Kustomer only contacts candidates from company email addresses ending in kustomer.com and does not seek funds from candidates in any circumstances.