Software Engineer, Fullstack – AI Platform

About this role

<div class="content-intro"><p><span style="text-decoration: underline;"><strong>Who We Are</strong></span></p> <p>Addepar is a global data and AI platform empowering investment professionals to turn complex financial information into actionable intelligence. Addepar unifies portfolio, market and client data in a total portfolio view and delivers AI-powered insights within investment and client workflows. More than 1,400 firms in nearly 60 countries use Addepar to manage and advise on nearly $9 trillion in assets. Its open platform integrates with nearly 650 software, data and consulting partners to power end-to-end investment operations across firms of all sizes and complexity. Addepar supports clients worldwide with offices in New York City, Salt Lake City, London, Edinburgh, Pune, Dubai, Geneva and São Paulo. </p></div><h4><span style="text-decoration: underline;"><strong>The Role</strong></span></h4> <p>We are currently seeking a Software Engineer, Fullstack to join the AI Platform team, which powers intelligent experiences across our AI products.                                                                                      </p> <p>As a Fullstack Engineer, you'll build and ship features across both the backend services and frontend interface of the AI Platform — spanning Python FastAPI/Flask microservices, AWS Lambda, DynamoDB, Redis, WebSocket streaming, and a Svelte-based real-time chat UI. You'll work across the full stack to deliver features for Addison, Addepar's AI-powered assistant. Current capabilities include conversational portfolio analysis, specialized agents for data operations and reporting workflows, dynamic chart generation, and real-time streaming interactions — with new agent capabilities and integrations shipping regularly.</p> <p>Day to day, you'll be writing backend services, building streaming UIs, and connecting the two — delivering complete features in a team where AI products move fast and your work reaches users directly.</p> <p>Applicants must have legal authorization to work in the country where this role is based on the first day of employment. Visa sponsorship is not available for this position.</p> <p><span style="text-decoration: underline;"><strong>What You’ll Do</strong></span><strong><br></strong></p> <ul> <li>Build and maintain backend services that power AI Platform products, developing in Python or other modern backend languages with emphasis on reliability and maintainability. </li> <li>Build and evolve REST APIs — including request validation, error handling, and clear API contracts between frontend and backend. </li> <li>Work with relational and/or NoSQL data models across systems such as MySQL, PostgreSQL, DynamoDB, and Redis. </li> <li>Build and maintain asynchronous processing flows using queues and worker-based systems.</li> <li>Build real-time UI features for conversational interfaces — including chat streaming, incremental rendering, and dynamic layouts. </li> <li>Work with WebSocket pipelines to handle streamed data, retries, and reconnection gracefully. </li> <li>Implement state management for streaming UIs, handling partial data, scroll behavior, and UI correctness over time. </li> <li>Deliver features end-to-end — owning both backend logic and the frontend implementation that consumes it.  </li> <li>Write strong automated tests, including unit and integration coverage across both backend (pytest) and frontend (Vitest, Playwright), and contribute to CI-based quality gates.</li> <li>Debug production issues across service and UI boundaries using logs, metrics, browser DevTools, and system reasoning.</li> <li>Contribute to code reviews, system quality, and engineering standards across the team. </li> <li>Grow your skills in your secondary stack with support from senior engineers and through hands-on feature delivery. </li> </ul> <h4><span style="text-decoration: underline;"><strong>Who You Are</strong></span><strong><br></strong></h4> <ul> <li>Bachelor’s degree in Computer Science, Engineering, or related technical field (or equivalent practical experience).</li> <li>At least <strong>three years of professional fullstack development</strong> experience in a production environment.</li> <li>Strong in one area (backend or frontend) with demonstrable, production-level depth — not surface-level familiarity.</li> <li>Evident experience in the other area — has shipped real features (not just tutorials or side projects) on the complementary side of the stack, with clear desire to grow there.</li> <li>Proficiency in at least one production backend…