Senior Software Engineer, Machine Learning & Simulations Platform

About Upstart

Upstart is the leading AI lending marketplace partnering with banks and credit unions to expand access to affordable credit. By leveraging Upstart's AI marketplace, Upstart-powered banks and credit unions can have higher approval rates and lower loss rates across races, ages, and genders, while simultaneously delivering the exceptional digital-first lending experience their customers demand. More than 80% of borrowers are approved instantly, with zero documentation to upload.

Upstart is a digital-first company, which means that most Upstarters live and work anywhere in the United States. However, we also have offices in San Mateo, California; Columbus, Ohio; Austin, Texas; and New York City, NY (opening Summer 2026).

Most Upstarters join us because they connect with our mission of enabling access to effortless credit based on true risk. If you are energized by the impact you can make at Upstart, we’d love to hear from you!

The Team

The Machine Learning & Simulations Platform (MLSP) team builds and operates the core infrastructure that powers ML model training, inference, and marketplace simulation at Upstart. Our platform is foundational to the company’s success—every underwriting, fraud, conversion, and verification model runs here. We also provide the simulation capabilities that help teams experiment safely and assess business impact without requiring costly live experimentation.

We are on a mission to reimagine our infrastructure to support the growing complexity of our ML models, the demand for low-latency inference, and the accuracy needed to simulate the dynamics of our borrower‑lender marketplace at scale. The team partners closely with Engineering, ML, Product, and Finance to accelerate innovation while safeguarding performance and integrity.

As a Senior Software Engineer on the MLSP 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
• Enable the modernization of our serving infrastructure, reducing inference latency to just a few seconds for our most complex models
• 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 including several building and contributing to in‑house Machine Learning Platforms
• Experience building and maintaining backend software services and APIs
• Proficiency with some or many of the following: Python, Kotlin, Databricks, and AWS
• Exhibits a growth mindset - you’re not afraid to pick up new technologies that are best for the task, and learn from others.
• Ability to quickly comprehend and reiterate complex requirements from product or engineering leadership and translate those to both technical and non‑technical stakeholders
• Track record of successfully mentoring and developing other engineers around you while seeking out and appreciating constructive feedback

Preferred Qualifications

• Familiarity with model serving technologies like Ray, simulation platforms, experimentation frameworks
• Proficiency with Flask, FastAPI, Metaflow, MLflow, gRPC, Kafka, Spark/PySpark, ETL/ELT, Redshift (or similar)
• Excellent quantitative reasoning skills with interest in working at the intersection of engineering and machine learning
• Strong sense of ownership and accountability for the quality and timely delivery of work
• Proven ability to effectively analyze and solve complex problems
• Excellent written and verbal communication skills with stakeholders, peers and product owners
• Ability to thrive both in self‑directed work environments and in collaborative settings, contributing positively to team dynamic

Position location

This role is available in the following locations: Remote-US

Time zone requirements

The team operates on the East/West coast time zones.

Travel requirements

As a digital first company, the majority of your work can be accomplished remotely. The majority of our employees can live and work anywhere in the U.S but are encouraged to still spend high quality time in‑person collaborating via regular onsites. The in‑person sessions’ cadence varies depending on the team and role; most teams meet once or twice per quarter for 2‑4 consecutive days at a time.

What you’ll love

• Competitive Compensation (base + bonus & equity)
• Comprehensive medical, dental, and vision coverage with Health Savings Account contributions from Upstart
• 401(k) with 100% company match up to $4,500 and immediate vesting and after‑tax savings
• Employee Stock Purchase Plan (ESPP)
• Life and disability insurance
• Generous holiday, vacation, sick and safety leave
• Supportive parental, family care, and military leave programs
• Annual wellness, technology & ergonomic reimbursement programs
• Social activities including team events and onsites, all‑company updates, employee resource groups (ERGs), and other interest groups such as book clubs, fitness, investing, and volunteering
• Catered lunches + snacks & drinks when working in offices

Base Salary

At Upstart, your base pay is one part of your total compensation package. The anticipated base salary for this position is expected to be within the below range. Your actual base pay will depend on your geographic location – with our “digital first” philosophy, Upstart uses compensation regions that vary depending on location. Individual pay is also determined by job‑related skills, experience, and relevant education or training. Your recruiter can share more about the specific salary range for your preferred location during the hiring process.

In addition, Upstart provides employees with target bonuses, equity compensation, and generous benefits packages (including medical, dental, vision, and 401k).

United States | Remote - Anticipated Base Salary Range

$163,600—$226,400 USD

Equal Opportunity Employer

Upstart is a proud Equal Opportunity Employer. Just as we are dedicated to improving access to affordable credit for all, we are committed to inclusive and fair hiring practices.

If you require reasonable accommodation in completing an application, interviewing, completing any pre‑employment testing, or otherwise participating in the employee selection process, please email [email protected].