Senior Vanilla JavaScript Developer in United States at Jobgether

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Senior Vanilla JavaScript Developer based in the United States.

This role is focused on building high-performance, framework-agnostic web applications using modern Vanilla JavaScript and core web technologies. You will design and deliver scalable front-end solutions that prioritize performance, maintainability, and exceptional user experience without relying heavily on frameworks. The position involves close collaboration with product managers, designers, backend engineers, and client stakeholders across distributed, U.S.-aligned teams. You will contribute to architectural decisions, optimize complex web interfaces, and ensure applications meet high standards for speed, accessibility, and responsiveness. This is a hands-on engineering role for someone who thrives in deep JavaScript craftsmanship and enjoys solving browser-level challenges in fast-moving environments. You will also play a mentoring role, supporting junior developers and helping elevate engineering practices across teams.

In this role, you will be responsible for designing, developing, and optimizing complex web applications built primarily with Vanilla JavaScript, ensuring strong performance, scalability, and clean architecture. You will work across the full front-end lifecycle while collaborating closely with cross-functional teams and client stakeholders.

• Design and build large-scale, framework-agnostic web applications using Vanilla JavaScript (ES6+), HTML5, and CSS3
• Develop reusable UI components and maintain clean, modular, and efficient codebases
• Optimize application performance, responsiveness, accessibility, and Core Web Vitals metrics through advanced DOM and browser API techniques
• Integrate front-end applications with REST APIs, WebSockets, and backend services
• Collaborate with designers, product managers, engineers, and client teams to deliver high-quality user experiences
• Conduct code reviews and mentor junior developers, promoting best practices and engineering excellence
• Implement automated testing strategies and contribute to CI/CD pipelines to ensure reliable deployments
• Troubleshoot and resolve complex browser compatibility, performance, and scalability issues

This role requires deep expertise in Vanilla JavaScript and strong front-end engineering fundamentals, along with the ability to work effectively in client-facing and distributed team environments. You should be highly independent, detail-oriented, and comfortable solving complex technical challenges at scale.

• 5+ years of professional front-end development experience
• Expert-level proficiency in Vanilla JavaScript (ES6+) and deep understanding of core language concepts (closures, scope, prototypes, event loop, async patterns)
• Strong experience with semantic HTML5, advanced CSS3, and responsive design principles
• Experience integrating front-end applications with RESTful APIs and real-time communication systems
• Familiarity with modern build tools such as Webpack, Babel, Rollup, or Vite
• Experience with Git and collaborative development workflows
• Strong English communication skills and experience working with distributed, cross-functional teams
• Ability to work independently while collaborating effectively with U.S.-based clients and stakeholders
• Experience with testing frameworks (Jest, Playwright, Cypress), TypeScript, or Node.js is a plus
• Exposure to Web Components, CI/CD pipelines, or cloud environments is a bonus

• Competitive compensation aligned with experience
• Fully remote work environment with flexible collaboration across time zones
• Opportunity to work directly with U.S.-based clients on impactful projects
• Professional growth through mentoring, code reviews, and technical leadership opportunities
• Exposure to modern engineering practices, tools, and distributed team environments
• Collaborative and engineering-focused culture emphasizing quality and ownership
• Long-term engagement opportunities in a high-growth consulting environment