[Remote] Principal Software Engineer, Machine Learning Simulations

Note: The job is a remote job and is open to candidates in USA. Upstart is a leading AI lending marketplace focused on reducing the cost and complexity of borrowing for Americans. They are seeking a Principal Software Engineer specializing in Machine Learning Simulations to build an MLOps platform and support rapid innovation across teams.ResponsibilitiesBuild, maintain, and optimize Upstart’s next-generation machine learning and simulation platform, enabling increased scale, performance, and confidence in decisioningDevelop high-quality software applications that enable machine learning models to be applied to the ever-evolving needs of the businessEnable the modernization of our serving infrastructure, reducing inference latency to just a few seconds for our most complex modelsDesign and contribute to our simulation systems to more accurately reflect production environments, reducing simulation cost and enabling broader usage across teamsCommunicate closely with cross-functional partners from ML, Engineering, Product, and Data Engineering teams, keeping all stakeholders informedMentor engineers across the team, sharing expertise on distributed systems, MLOps, and scalable architectureSkillsBachelor's degree in Computer Science, Engineering, or Mathematics, or a related field (or its equivalent) + 8 years of experienceExperience building or contributing to platforms or systems that support machine learning model simulationExperience building self-serve or configuration-driven tooling for internal stakeholdersExperience building and maintaining backend software services and APIsProficiency with some or more of the following: Python, Kotlin, Databricks, and AWSExhibits a growth mindset - you're not afraid to pick up new technologies that are best for the task, and learn from othersAbility to quickly comprehend and reiterate complex requirements from product or engineering leadership and translate those to both technical and non-technical stakeholdersTrack record of successfully mentoring and developing other engineers around you while seeking out and appreciating constructive feedbackFamiliarity with model serving technologies like Ray, and experimentation frameworksProficiency 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 learningStrong sense of ownership and accountability for the quality and timely delivery of workProven ability to effectively analyze and solve complex problemsExcellent written and verbal communication skills with stakeholders, peers and product ownersAbility to thrive both in self-directed work environments and in collaborative settings, contributing positively to team dynamicBenefitsTarget bonusesEquity compensationGenerous benefits packages (including medical, dental, vision, and 401k)Competitive compensation, including base pay, bonus opportunities, and annual equity grants that vest quarterlyRetirement benefits to help you plan for the future, including a 401(k) or Group Retirement Savings Plan with a company match of $2 for every $1 contributed, up to $15,000 annually (USD in the US, CAD in Canada)Employee Stock Purchase Plan (ESPP) with discounted stock purchase options for eligible employees (US only)Comprehensive health coverage designed to support you and your family, including medical, dental, vision, and wellness resources for US and supplemental health coverage for Canada.Health Savings Account contributions from Upstart for eligible plans (US only)Income protection benefits, including life insurance and disability coverage for added financial securityPaid time off, sick leave, and company holidays, in line with local requirementsPaid family and parental leave to support caregiving and major life moments (duration varies by country)Family-centered benefits to support fertility, parenthood, and caregiving needsEmployee Assistance Program (EAP) offering mental health support and life-centered resourcesFinancial wellness resources, including access to financial planning tools and a financial concierge service (US Only)Annual wellness allowance to support your physical and emotional well-being and personal development, based on what matters most to youAnnual productivity allowance to invest in relevant tools and resources you need to do your best work, no matter where you work fromConnection and community through team events, all-company updates, and employee resource groups (ERGs)Onsite perks, including catered lunches and fully stocked micro-kitchens when working from one of our offices in the Bay Area, Austin, Columbus, and New York City (opening Summer 2026!)Company OverviewUpstart is a leading AI lending marketplace partnering with banks and credit unions to expand access to affordable credit. It was founded in 2012, and is headquartered in San Mateo, California, USA, with a workforce of 1001-5000 employees. Its website is https://upstart.com/about.