Nextmark

Java Developer

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

  • Design, develop, and optimize REST and GraphQL endpoints for scalable APIs.
  • Drive data validation, error handling, and security best practices within backend services.
  • Plan and execute database migrations, optimizations, and schema changes as needed.
  • Actively test new AI-powered models in Cursor, providing actionable feedback via incident reports, bug traces, and screenshots.
  • Participate in 4-day intensive testing bursts, exploring how AI models impact real coding workflows.
  • Engage thoughtfully with the research team in a dedicated Slack channel to discuss findings and propose improvements.
  • Submit detailed post-burst surveys, delivering insights on model performance and developer experience.

Required Skills & Qualifications

  • 3+ years of professional experience as a backend developer, with strong expertise in Java.
  • Proficient in building and maintaining RESTful and GraphQL APIs.
  • Advanced understanding of backend data validation, error handling, and API security.
  • Hands-on experience with database migrations, performance tuning, and schema design.
  • Extensive use of AI tools for coding; familiarity with Cursor is highly desirable.
  • Outstanding written and verbal communication skills, with a knack for clear incident and bug reporting.
  • Proven ability to thrive in fast-paced, confidential, and collaborative remote environments.

Preferred Qualifications

  • Visible contributions to open source (e.g., GitHub stars or contributions).
  • Experience designing or evaluating experimental tooling and developer workflows.
  • Demonstrated enthusiasm for AI advancements in software development.

$50–$120/hr

Remote