Senior API Engineer

Upwork ($UPWK) is the world’s human and AI-powered work marketplace that connects businesses with highly skilled, AI-enabled independent talent from across the globe. From entrepreneurs to Fortune 100 enterprises, companies rely on Upwork’s trusted platform and its mindful AI companion, Uma, to find and hire expert talent, leverage AI-powered work solutions, and drive business transformation. With on-demand access to professionals spanning more than 10,000 skills across AI & machine learning, software development, sales & marketing, customer support, finance & accounting, and more, Upwork enables businesses of all sizes to scale, innovate, and build agile teams for the age of AI and beyond.

Upwork’s platform has facilitated more than $25 billion in economic opportunity for talent around the world. Learn more at Upwork.com and follow us on LinkedIn, Facebook, Instagram, TikTok, and X.

We’re looking for a Senior API Engineer to join our AI/ML team and help build the next-generation Services Interface that fuels business growth. In this role, you’ll collaborate with talented engineers across the company to design, secure, and optimize APIs that power innovative experiences for millions of users. You’ll take ownership of projects that have a direct impact, contribute to shaping our API standards, and grow your technical leadership skills while working on complex, high-visibility initiatives.

• Design, build, and maintain APIs for the AI/ML Services Interface with reliability, scalability, and performance as core priorities.

• Partner with frontend and backend engineers to define API contracts and deliver seamless integrations.

• Implement and strengthen API security, authentication, and authorization mechanisms.Conduct code reviews, provide constructive feedback, and ensure adherence to engineering best practices.

• Monitor, troubleshoot, and continuously improve API performance and developer experience.

• Stay current with API development trends, frameworks, and tools, sharing insights with the team. 

• Strong knowledge of Go, or demonstrated ability and motivation to quickly learn it, applying best practices effectively.

• Proven experience designing and shipping APIs that meet real-world application needs.

• Familiarity with API documentation practices and tools that make interfaces easy to understand and adopt.

• Track record of solving complex technical challenges with creativity and pragmatism. 

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 34 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 to learn more about opportunities 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.