Senior/Lead JavaScript Developer

Senior/Lead JavaScript Developer

Company: Upwork

Location: Brazil (Remote)

Employment Type: Contract (with potential renewal)

About the Role:

Join Upwork’s Hybrid Workforce Solutions (HWS) Team to design and build high-performance, scalable systems that deliver exceptional user experiences for millions of professionals and clients worldwide. Solve critical technical and product challenges while working collaboratively in an agile environment.

Responsibilities:

• Collaborate with stakeholders to understand and deliver project requirements.
• Design, develop, test, and maintain scalable server-side logic, databases, and APIs.
• Write front-end code using TypeScript or JavaScript.
• Develop front-end applications using modern frameworks such as Vue.js (preferred), Nuxt, React.js, or Angular.
• Optimize front-end performance and ensure cross-browser compatibility.
• Integrate front-end interfaces with backend APIs for smooth data flow.
• Improve code quality, documentation, and reduce technical debt.
• Participate in code and design reviews.
• Document code and technical specifications.
• Monitor system performance and respond to incidents during on-call rotations.
• Engage in Scrum ceremonies and collaborate during core Pacific Time hours (8:00 am – 11:00 pm), occasionally until midnight.
• Manage time independently to meet project deliverables (~40 hours/week).

Required Skills:

• 8+ years of professional software development experience.
• Deep knowledge of modern JavaScript (ES6+) or TypeScript, CSS, and HTML.
• Extensive experience with modern JS frameworks (Vue preferred, React or Angular).
• Flutter or mobile development experience is a plus.
• Experience with unit testing and end-to-end UI testing.
• Basic understanding of accessibility (WCAG) guidelines.
• Self-motivated, organized, and able to learn independently.
• Intermediate English proficiency (capable of technical interviews in English).
• Basic knowledge of PHP, server-side JavaScript/TypeScript, Node.js backend framework.
• Understanding of system design principles and RESTful APIs.
• Experience writing maintainable unit tests.
• Familiarity with relational databases.
• Experience working with distributed engineering teams.
• Comfortable working with AWS.
• Experience with high-load web applications and scalability challenges.