Nextmark

Senior Full-Stack Software Engineer

Contractor · Remote · 10 openings

In this role, you'll apply your expertise to help train next-generation AI systems. Your work will shape how models learn, reason, and perform through high-quality, real-world input. No prior experience in AI is required — your domain knowledge is what matters.

Key Responsibilities

  • Lead the end-to-end design, development, and deployment of robust web applications leveraging React and Node.js.
  • Define and implement scalable, maintainable, and secure system architectures.
  • Mentor, support, and elevate fellow engineers through technical guidance and code reviews.
  • Drive and enforce best practices in coding standards, testing, and documentation.
  • Collaborate closely with product and design teams to deliver seamless user experiences.
  • Identify and resolve technical challenges, continuously improving application performance and reliability.
  • Champion clear, effective written and verbal communication to foster alignment across teams.

Required Skills & Qualifications

  • Expertise in JavaScript, with advanced proficiency in React and Node.js ecosystems.
  • Deep understanding of RESTful APIs, microservices, and modern web application architecture.
  • Proven experience architecting, building, and deploying scalable full-stack solutions.
  • Strong knowledge of security best practices for both frontend and backend development.
  • Exceptional written and verbal communication skills, essential for remote collaboration.
  • Demonstrated ability to mentor and develop engineering talent.
  • Self-motivated, detail-oriented, and passionate about code quality and best practices.

Preferred Qualifications

  • Experience with Python for backend development.
  • Background in cloud infrastructure and DevOps practices.
  • Prior leadership or technical lead experience in a fast-paced, remote environment.

$30–$90/hr

Remote