Senior Backend Engineer - Fynn (AI Credit Coach)

About this role

<div class="content-intro"><p data-pm-slice="1 1 []"><strong>Kikoff: The Fintech Powering Financial Security at Scale</strong><br>Kikoff is a profitable, pre-IPO fintech company on a mission to empower everyone to achieve financial security. With record revenue growth in 2025 and a unicorn valuation, we've built a suite of products that help millions of people build credit, access liquidity, and save money.<br>We're scaling fast. Join us if you want to build something meaningful and help millions of people move forward financially.</p> <p>&nbsp;</p> <p><strong>Why Kikoff:</strong></p> <p>This is a consumer fintech startup, and you will be working with serial entrepreneurs who have built strong consumer brands and innovative products. We value extreme ownership, clear communication, a strong sense of craftsmanship, and the desire to create lasting work and work relationships. Yes, you can build an exciting business AND have real-life real-customer impact.</p></div><h3>About Fynn (AI Credit Coach)</h3> <p>Fynn is Kikoff's AI credit coach, and the intelligence layer across our entire ecosystem. Rather than offering generic advice, Fynn analyzes a user's credit report and financial profile to deliver highly personalized answers, surface the next steps that matter most for their goals, and connect them directly to the tools that help them take action, from credit-building to AI-powered debt negotiation, all within Kikoff.</p> <p>Fynn is already one of the most-used surfaces in the Kikoff app, and early engagement shows real demand for guidance people can actually act on. Debt is the single most common topic users bring to it, and from a single chat a user can launch our voice agent to negotiate with creditors on their behalf. Members who lean on Fynn tend to make faster progress on their credit, and we're still early in what it can become.</p> <p>We're looking for a Senior Backend Engineer to help take Fynn from a powerful reactive assistant to a proactive coach that anticipates user needs and prevents credit mistakes before they happen. You'll own the backend systems that power personalization, orchestrate LLM and agent workflows, and turn millions of conversations into measurable financial progress at scale, in a regulated environment where accuracy and trust are non-negotiable.</p> <p><a href="https://www.businesswire.com/news/home/20260407281130/en/Kikoff-Launches-Fynn-an-AI-Credit-Coach-to-Accelerate-Personalized-Financial-Progress-for-Consumers">Read more about Fynn's launch and early impact</a></p> <h3>What You'll Be Doing</h3> <ul> <li><strong>Design and implement</strong> the core backend systems behind Fynn: the conversational AI layer, personalization engine, and the orchestration that connects users to Kikoff's suite of tools and marketplace offerings.</li> <li><strong>Build LLM-powered workflows and agents</strong>, integrating model providers, retrieval over user credit and financial data, tool-calling, and the AI Debt Negotiation voice agent into reliable, production-grade pipelines.</li> <li><strong>Own the evaluation and quality infrastructure</strong> that lets us ship safely, including automated scorers across accuracy, tone, compliance, and privacy, plus the tooling to test prompt and model changes before they reach users.</li> <li><strong>Turn insight into action at scale</strong>, building the systems that detect financial challenges in a user's profile and surface tailored, timely next steps across the user lifecycle.</li> <li><strong>Integrate with internal services and third-party providers</strong> such as credit bureau data, financial profiles, and Kikoff's product surfaces, building robust APIs and data pipelines that maintain accuracy and consistency for millions of users.</li> <li><strong>Enhance observability and reliability</strong>, introducing monitoring, alerting, latency management, and fault tolerance into AI-critical systems where a wrong answer carries real consequences.</li> <li><strong>Help evolve Fynn from reactive to proactive</strong>, building the foundations for anticipatory guidance that reaches users at the right moment.</li> <li><strong>Work closely with our product, data science, and operations teams</strong> to ship features that directly impact our customers' financial wellbeing while maintaining the highest standards of reliability, compliance, and security.</li> </ul> <h3>What We're Looking For</h3> <ul> <li>5+ years of experience with modern backend frameworks and a track record of building and scaling production systems</li> <li>Strong systems design skills; you've architected and shipped distributed systems that handle high throughput and maintain data consistency</li> <li>Track record of making infrastructure decisions that balance technical excellence with business pragmatism</li> <li>Production experience with background job processing systems (Sidekiq, Resque, or similar)</li> <li>Solid understanding of database optimization, caching strategies, and performance tuning</li> <li>Comfort building in an environment where correctness, latency, and user trust all matter at once</li> </ul> <h3>Ideal Candidate Also Has</h3> <ul> <li>Hands-on experience building LLM-powered products such as RAG, agentic/tool-calling workflows, prompt engineering, or eval frameworks</li> <li>Experience working within a client-server architecture, even if only on one side of it (backend services, the client/mobile app, or the API contract between them)</li> <li>Experience with AI quality and safety systems: automated evaluation, guardrails, and testing model/prompt changes before release</li> <li>Experience with payment systems, financial infrastructure, or regulated environments (ACH, card processing, credit bureau data)</li> <li>Background in fintech, payments, or lending infrastructure</li> <li><strong>Technical Leadership:</strong> Ability to own complex technical initiatives end-to-end, from design through implementation and rollout</li> <li><strong>Mento