Senior Lead Machine Learning Engineer

Upwork ($UPWK) is the world’s largest work marketplace, connecting businesses with highly skilled professionals worldwide. From entrepreneurs to Fortune 100 enterprises, companies trust Upwork’s platform to access expert talent, leverage AI-powered work solutions, and drive meaningful business outcomes.

Upwork’s AI-powered platform has facilitated over $20 billion in economic opportunity for professionals worldwide. With professionals spanning 10,000+ skills, including AI and machine learning, software development, sales and marketing, customer support, finance and accounting, and more, Upwork empowers businesses of all sizes to scale, innovate, and build agile teams.

Are you passionate about using machine learning to drive meaningful change? As a Senior Lead Machine Learning Engineer at Upwork, you will play a pivotal role in developing and scaling impactful ML models that power the experiences of millions of users. From improving search relevance to personalizing recommendations and enhancing fraud detection, your work will directly shape how talent and clients connect on the world’s largest work marketplace. You’ll collaborate across disciplines, own mission-critical initiatives, and bring forward innovative solutions that enable the future of work.

Responsibilities

• Design, develop, and deploy production-grade ML models that drive core user-facing features including recommendations, search, personalization, and trust & safety.

• Lead complex cross-functional initiatives by aligning stakeholders, translating strategy into execution, and delivering measurable business impact.

• Optimize model performance and infrastructure, championing operational excellence and responsiveness at scale across Upwork's ecosystem.

• Guide the team in setting and upholding best practices for experimentation, data quality, and model evaluation to support continuous learning and delivery.

• Use advanced analytics to surface insights and influence decision-making at the team and leadership level.

• Mentor and support team members, cultivating a collaborative, curious, and inclusive engineering culture.

• Bring fresh ideas and frameworks to solve technical challenges, championing innovation and creative problem-solving across projects.

What it takes to catch our eye

• Extensive experience developing and deploying ML models at scale, including deep learning, NLP, or recommender systems in real-world applications.

• Fluency in Python and ML libraries such as TensorFlow or PyTorch, and strong proficiency with data tools like SQL, Spark, and Pandas.

• Proven ability to lead high-impact projects from ideation through deployment, working effectively with cross-functional teams.

• Strong communication skills with the ability to explain technical decisions and data insights to stakeholders at all levels.

• A growth-oriented mindset with a passion for innovation, learning, and advancing the state of applied machine learning.

Come change how the world works.

At Upwork, you’ll shape the future of work for a global, remote-first workforce, creating economic opportunities for professionals worldwide. While we have a physical office in Palo Alto, we currently hire full-time employees in 21 U.S. states, making it easier than ever to join our mission from wherever you call home.

Our culture is built on trust, risk-taking, customer focus, and excellence, all in service of our core mission: to create economic opportunities so people have better lives. We embrace authenticity and inclusion, encouraging everyone to bring their whole selves to work. Personal and professional growth is a priority here, supported through development programs, mentorship, and our Upwork Belonging Communities.

We’re proud to offer benefits that go beyond the basics, including comprehensive medical coverage for you and your family, unlimited PTO, a 401(k) plan with matching, 12 weeks of paid parental leave, and an Employee Stock Purchase Plan. Visit our Life at Upwork page to learn more about our values, working principles, and the overall employee experience.

Ready to help shape the future of work? Check out our Careers page and follow us on LinkedIn, Facebook, Instagram, TikTok, and X to learn more about life at Upwork.

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.