Senior Staff Software Engineer - Web Platform

Upwork ($UPWK) is the world’s work marketplace. We serve everyone from one-person startups to over 30% of the Fortune 100 with a powerful, trust-driven platform that enables companies and talent to work together in new ways that unlock their potential.  

Last year, more than $3.8 billion of work was done through Upwork by skilled professionals who are gaining more control by finding work they are passionate about and innovating their careers. 

This is an engagement through Upwork’s Hybrid Workforce Solutions (HWS) Team. Our Hybrid Workforce Solutions Team is a global group of professionals that support Upwork’s business. Our HWS team members are located all over the world.

Upwork is undergoing a platform transformation to meet the evolving demands of AI-native product experiences. As a Staff Software Engineer on the Web Platform team, you will lead the design and development of our next-generation web architecture, empowering teams across Upwork to build dynamic, agent-driven user interfaces with speed and confidence.

You’ll play a pivotal role in defining how our platform supports modular, performant, and scalable frontend experiences. This includes driving the adoption of federated app shell architecture, pioneering horizontal micro apps, and optimizing developer workflows to support modern AI toolkits. If you thrive at the intersection of architecture, performance, and developer experience and are excited by the opportunity to shape future AI experiences, this is the role for you.

Work/Project Scope:

• Architect and build modular frontend infrastructure with hybrid rendering (SSR, edge functions, client hydration) to support dynamic AI-native UIs.

• Lead development of an app shell model to enable federated delivery of horizontal micro frontends across teams, with strong ownership boundaries and runtime flexibility.

• Develop and evangelize AI toolkit components, enabling common interaction patterns (clarify, retry, fallback, tone) to be reused across the platform.

• Set technical direction and collaborate with platform leads, design systems, and developer tooling teams to ensure consistency, governance, and rapid iteration support.

• Evaluate and scale frameworks (e.g., React, Next.js) that align with emerging LLM agent SDKs and support agentic UI flows.

• Mentor engineers and contribute to technical leadership across Product Engineering through architecture reviews, design discussions, and shared learning.

• Collaborate cross-functionally with Product, Design, and Infrastructure teams to align platform capabilities with user-facing needs.

Must Haves (Required Skills):

• 8+ years of experience in frontend development with deep knowledge of modern frameworks (React, Vue, Next.js, etc.) and native browser APIs.

• Strong understanding of web architecture principles: security by design, server/client rendering paradigms, hydration techniques, micro frontends.

• Experience designing for runtime UI composition, shared component governance, and telemetry/a11y/compliance hooks.

• Deep knowledge of building for performance at scale: modular loading, edge delivery, multi-level caching, streaming responses.

• Passion for AI-native patterns and agentic workflows; familiarity with LLM SDKs and AI UI concepts a plus.

• Proven track record of leading architectural transitions in complex product ecosystems.

• Excellent communication and collaboration skills, especially in cross-team roles.

Nice to have Skills:

• Hands-on work with observability pipelines, and build/deployment tooling.

• Familiarity with widget-based delivery, embeddable apps, cross-context communication.

• Prior experience in a high-scale consumer or enterprise SaaS environment.

• Contributions to internal or open-source design systems or component libraries.

Upwork is proudly committed to fostering a diverse and inclusive workforce. We never discriminate based on race, religion, color, national origin, gender (including pregnancy, childbirth, or related medical condition), sexual orientation, gender identity, gender expression, age, status as a protected veteran, status as an individual with a disability, or other applicable legally protected characteristics. 

 Additionally, a criminal background check may be run on a candidate after a conditional offer to perform your services for Upwork 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.