Sr Lead AI Research Scientist, AI Foundations

Upwork Inc.'s (Nasdaq: UPWK) family of companies connects businesses with global, AI-enabled talent across every contingent work type including freelance, fractional, and payrolled. This portfolio includes the Upwork Marketplace, which connects businesses with on-demand access to highly skilled talent across the globe, and Lifted, which provides a purpose-built solution for enterprise organizations to source, contract, manage, and pay talent across the full spectrum of contingent work. From Fortune 100 enterprises to entrepreneurs, businesses rely on Upwork Inc. to find and hire expert talent, leverage AI-powered work solutions, and drive business transformation. With access to professionals spanning more than 10,000 skills across AI & machine learning, software development, sales & marketing, customer support, finance & accounting, and more, the Upwork family of companies enables businesses of all sizes to scale, innovate, and transform their workforces for the age of AI and beyond.

Since its founding, Upwork Inc. has facilitated more than $30 billion in total transactions and services as it fulfills its purpose to create opportunity in every era of work. Learn more about the Upwork Marketplace at Upwork.com and follow us on LinkedIn, Facebook, Instagram, TikTok, and X; and learn more about Lifted at Go-Lifted and follow on LinkedIn.

The AI Foundations team is responsible for core research and development around training, evaluation, and deployment of AI models including but not limited to custom Large Language Models (LLMs) and other Generative AI systems to support Uma, Upwork’s flagship AI model. We are a team of passionate AI researchers, engineers, and infrastructure specialists building towards highly reliable and intelligent AI systems to support the world’s largest marketplace for work.  

As a Sr Lead AI Research Scientist within the AI Foundations Team, you will play a pivotal role in designing and researching novel algorithms for building reliable AI models and collaborate with engineers, data scientists, and product leaders to turn research into transformative impact within complex customer-facing AI products. A suitable candidate for this role can work effectively bottom up and take research projects from ideation to publication, and we also list some topics of interest below. Your work will form the backbone for development of Upwork’s core AI capabilities as well as enabling complex AI products that involve embedding-based retrieval loops and multi-agent setups. You will also represent Upwork as a thought leader within the AI space by publishing and presenting state-of-the-art AI research at top AI conferences.

Responsibilities:

• Research core algorithms for AI systems within topics that are core to Upwork’s mission of building reliable AI to help humans do work faster and better. 
• Prioritize research into building production-grade customer-facing AI models, with special emphasis on methods to evaluate AI outputs and measure+mitigate reliability gaps such as AI uncertainty and hallucinations. For other topics of interest please look below.
• Work crossfunctionally with other engineering teams to integrate research results into complex systems that include embedding/retrieval systems and/or multi-agent setups for transformative downstream product impact.
• Own research projects from start to finish, from ideation to hypothesis testing to POC building to final compilation of results and publication. 
• Consider the effects of projects across multiple teams and proactively manage conflicts. Work together with partner teams to achieve cross-departmental goals and satisfy broad requirements.
• Collaborate and publish with other machine learning researchers and data scientists on novel AI research at top AI conferences such as NeurIPS, ICML, and ICLR.
• Stay current with the latest advancements in ML/AI research, and disseminate information across the company as appropriate to raise the bar on ML/AI literacy across all Upwork business units.
• Mentor junior researchers and engineers and lead research projects with medium-to-large teams to achieve larger-scale seminal results.
• Mentor teammates, conduct code reviews, and uphold engineering best practices to ensure the delivery of high-quality solutions.
• Advise Upwork’s leadership team on AI advancements and help formulate AI strategy for the company as a whole.

Research Directions:

Although this role is largely bottom-up, here are some research directions we are especially interested in.

• AI reliability and robustness for addressing critical AI performance gaps in production-grade models.
  • Detection and mitigation of model uncertainty and/or hallucinations.
  • Methods to identify model failure modes and remedies thereof (e.g. collecting new data via active learning).
• AutoML/Continual Learning and data collection flywheels to continuously iterate AI models.
• Methods for generating diverse and customizable synthetic data.
• Methods for LLM personalization and memory.
• Research on novel modalities of human+AI collaboration.
• Agentic systems and workflows.
• New reinforcement learning algorithms utilizing novel modalities of feedback obtained directly from real-time, real-world data..

What it takes to catch our eye:

• PhD in a relevant field as well as Industry experience. 
• Multiple main-track first-or-last-author publications at top AI/ML conferences, such as ICLR, ICML, NeurIPS, CVPR, ECCV, ICCV, EMNLP, or ACL.
• Proven ability to mentor junior researchers/engineers and clearly communicate results to both technical and nontechnical audiences.
• High proficiency with Python, as well as PyTorch or equivalent deep learning frameworks. 
• Track record of working in startup-like environments that encourages bottom-up thinking and problem solving. Although at its core this is an AI research role, we are a new and growing AI organization that sometimes requires lateral thinking and “wearing many hats” to get things done.

Come change how the world works.

Upwork is establishing its first international operational hub in Lisbon, Portugal. The new office is expected to be fully operational by Q4 2026.

This position will initially be employed through a partner to ensure a seamless hiring process while we establish the hub. Once the hub is established, there may be opportunities to transition to employment with Upwork depending on business needs and other requirements. While employed by the partner, you’ll work as part of Upwork’s team, with access to our resources, culture, and growth opportunities.

Our partner will offer competitive benefits. When Upwork’s hub is established, we will be excited to offer employment and benefits directly as business needs require. 

Upwork is committed to building a diverse, inclusive, and equitable workforce. Employment decisions are made without regard to race, color, religion, gender, sexual orientation, gender identity, national origin, disability, or any other status protected by applicable law.

Upwork is an Equal Opportunity Employer committed to recruiting and retaining a diverse and inclusive workforce. We do not discriminate based on race, religion, color, national origin, gender (including pregnancy, childbirth, or related medical conditions), sexual orientation, gender identity, gender expression, age, status as a protected veteran, status as an individual with a disability, genetic information, or other legally protected characteristics under federal, state, or local law.

Please note that a criminal background check may be required once a conditional job offer is made. Qualified applicants with arrest or conviction records will be considered in accordance with applicable law, including the California Fair Chance Act and local Fair Chance ordinances. The Company is committed to conducting an individualized assessment and giving all individuals a fair opportunity to provide relevant information or context before making any final employment decision.

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