Senior Software Engineer, Core GenAI Platform

Upstart; United States; Remote; USD 125,000 - 150,000; Full time

Job summary

A leading AI lending marketplace is seeking a Senior Software Engineer for their Core GenAI Platform team. You will design and build a unified interface for interacting with large language models, enhancing AI tooling across the organization. This role requires a strong background in software engineering, especially with Python, and a collaborative approach to cross-functional projects. The position is remote, with occasional travel required for on-site team collaboration.

Benefits

Competitive compensation

Comprehensive medical, dental, and vision coverage

401(k) with company match

Employee Stock Purchase Plan

Generous leave policies

Wellness programs

Qualifications

• 6+ years of experience in object-oriented software engineering with a strong systems engineering background.
• Proven experience independently leading impactful, cross-functional, multi-quarter projects with mid-to-large teams.
• Strong stakeholder management skills.

Responsibilities

• Design and build a unified interface for securely interacting with large language models.
• Drive cross-functional adoption of AI tooling by delivering reusable components.
• Ensure the platform adheres to security and fairness standards.

Skills

Object-oriented software engineering

Backend development with Python

Microservices architecture

Hands-on experience with ML platforms

Strong communication skills

Tools

Kubernetes

Docker

Terraform

Prometheus

Grafana

Datadog

Job description

Overview

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 delivering the digital-first lending experience customers demand. More than 80% of borrowers are approved instantly, with zero documentation to upload.

Upstart is a digital-first company with most Upstarters working remotely across the United States. We also have offices in San Mateo, California; Columbus, Ohio; and Austin, Texas.

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

Upstart’s Core GenAI Platform team is building foundational infrastructure that democratizes access to generative AI/LLMs for every product and engineering team across the company.

Note: The team collaborates with Machine Learning, Product, and Compliance to ensure model integrations are performant, secure, and compliant. Whether embedding LLMs in user-facing products or optimizing backend workflows, this team makes it seamless for Upstart Engineering to adopt and scale GenAI company-wide.

Senior Software Engineer – Core GenAI Platform

As a Senior Software Engineer on Upstart's Core GenAI Platform team, you will help design and build a unified interface for securely interacting with large language models, abstracting model selection, prompt orchestration, evaluation, and scaling. You’ll help build a centralized GenAI layer that enables engineers to use best-in-class LLMs through clean APIs, configurable pipelines, and intuitive tooling. You will report to the Senior Director of Engineering and partner across ML, Product, and Compliance to ensure every model integration is secure and compliant.

Impact:

• Build the Core GenAI platform powering generative AI use cases across Upstart Engineering.
• Design and implement reliable infrastructure for model inference, prompt orchestration, and data workflows.
• Drive cross-functional adoption of AI tooling by delivering reusable components and intuitive interfaces; increase developer productivity through automation, metrics dashboards, and streamlined GenAI integrations.
• Set the technical roadmap for platform capabilities, balancing innovation with reliability and compliance.
• Partner with ML researchers, product engineers, and design to bridge experimentation and production.
• Ensure the platform adheres to emerging standards of security, fairness, and explainability for LLM systems.

What we’re looking for

Minimum requirements

• 6+ years of experience in object-oriented software engineering with a strong systems engineering background
• Proven experience independently leading impactful, cross-functional, multi-quarter projects with mid-to-large teams
• Backend development with Python (e.g., FastAPI, Flask), microservices architecture, and infrastructure tools like Kubernetes, Docker, and Terraform
• Hands-on experience building ML platforms or infrastructure for LLMs or inference systems
• Familiarity with observability tools (Prometheus, Grafana, Datadog) and data processing pipelines
• Strong written and verbal communication and a collaborative approach to cross-functional work
• Strong stakeholder management skills

Preferred qualifications

• Full Stack development with React or similar
• Proficiency with Kotlin or Java and the Spring ecosystem
• Experience with LLM toolchains such as LangChain, LlamaIndex, or OpenAI APIs
• Understanding of model inference optimization (quantization, ONNX, streaming)
• Exposure to retrieval-augmented generation (RAG), vector databases (e.g., FAISS, Pinecone), or prompt engineering
• Experience operationalizing LLMs in production, including latency management and prompt versioning
• Ability to influence platform direction and drive alignment across multiple engineering teams
• Awareness of LLM-specific risk domains, including hallucinations, fairness, and data privacy

Position details

Location: Remote, San Mateo, Columbus, Austin

Time Zone: The team operates across all U.S. time zones.

Travel: Regular on-site collaboration sessions, 3 days per quarter at a Upstart office. Upstart covers travel expenses if you need to travel to attend these meetups.

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 company match up to $4,500 and immediate vesting
• Employee Stock Purchase Plan (ESPP)
• Life and disability insurance
• Generous holiday, vacation, sick and safety leave
• Parental, family care, and military leave programs
• Wellness, technology & ergonomic reimbursement programs
• Team events, on-sites, ERGs, and other interest groups
• Catered lunches, snacks, and drinks when in offices

Equal Opportunity Employer. We celebrate diversity and are committed to inclusion in our hiring practices.

If you require reasonable accommodation in completing an application or participating in the selection process, please email [e-mail]

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