Senior Software Engineer - Machine Learning Platform

About Upstart At Upstart, we’re united by a mission that matters: to radically reduce the cost and complexity of borrowing for all Americans. Every day, we bring creativity, experimentation, and advanced AI to reshape access to credit, helping millions move forward financially with clarity and confidence. As the leading AI lending marketplace, we partner with banks and credit unions to expand access to affordable credit through technology that’s both radically intelligent and deeply human. Our platform runs over one million predictions per borrower using more than 3,000 signals, powering smarter, fairer decisions for millions of customers. But the numbers only hint at the impact. Every idea, every voice, and every contribution moves us closer to a world where credit never stands between people and their financial progress. We’re proudly digital-first, giving most Upstarters the flexibility to do their best work from wherever they thrive, alongside teammates across 80+ cities in the US and Canada. Digital-first doesn’t mean distant. We’re intentional about in-person connection through team onsites, planning sessions, and moments that spark creativity and trust. And whether you choose to work primarily from home or collaborate in-person from one of our offices in Columbus, Austin, the Bay Area, or New York City (opening Summer 2026), you’ll have the support to work in the way that works best for you. If you’re energized by tackling meaningful problems, excited to innovate with purpose, and motivated by work that truly matters, we’d love to hear from you. The Team: The Machine Learning and Simulations Platform (MLSP) team builds and operates the core infrastructure that powers ML model training,feature engineering, inference, and marketplace simulation at Upstart. Every underwriting, fraud, conversion, and verification model runs on this platform. We own the full production path: the data and features that feed a model, the infrastructure that serves it at decision time, the tooling that deploys it, and the simulation systems that predict business impact before a change goes live. We are reimagining that platform to keep pace with our ML teams. That work spans low latency and GPU model serving, self-service model deployment, a feature platform that gives ML one place to define and serve production features, and high fidelity marketplace simulation. The team partners closely with ML, Engineering, Product, Data Platform. As a Senior Software Engineer on the ML and Simulations Platform team at Upstart, you will be responsible for building an MLOps platform to support machine learning model inference, process automation, model deployment, and observability. Machine Learning is critical to Upstart’s core business, and our greatest competitive advantage lies in the fact that we’re able to innovate on our AI engine quickly. You will also help build a marketplace simulation platform to support rapid innovation across ML and Finance teams. How you’ll make an impact

Build, maintain, and optimize Upstart’s next-generation machine learning and simulation platform, enabling increased scale, performance, and confidence in decisioning. Develop high-quality software applications that enable machine learning models to be applied to the ever-evolving needs of the business Build self-service tooling so ML teams can register features and deploy models independently, and reduce the manual work the platform team absorbs today. Deliver the data and feature infrastructure behind every model, including feature definition, storage, serving, and offline to online parity. Design and contribute to our simulation systems to more accurately reflect production environments, reducing simulation cost and enabling broader usage across teams. Communicate closely with cross-functional partners from ML, Engineering, Product, and Data Engineering teams, keeping all stakeholders informed Mentor engineers across the team, sharing expertise on distributed systems,MLOps, and scalable architecture.

Minimum Qualifications

6+ years of software engineering experience. Experience building and maintaining backend software services and APIs. Experience with distributed systems or large scale data processing, using Spark, Databricks, Ray, or an equivalent. Experience with an ML platform or the ML production path, such as training pipelines, model serving, feature pipelines, or a training data platform. Proficiency with some or many of the following: Python, Kotlin, Databricks, and AWS. Exhibits a growth mindset. You pick up new technologies that fit the task, and you learn from others. Ability to quickly comprehend complex requirements from ML, product, or engineering leadership, and translate them for both technical and non-technical partners.

Preferred Qualifications

Skill with Metaflow, MLflow, gRPC, Spark/PySpark, dbt, Ray, GPU Knowledge of simulation, experimentation, or