Senior Full-Stack Engineer for AI Apps (Remote, Part-Time)

Jobgether; Spain; Remote; EUR 50,000 - 80,000; Full time

Benefits offered by this job

Flexible schedule

Fully remote opportunity

Part-time commitment

Output-based earnings

Fast onboarding

Job summary

Jobgether is seeking a Sr. Full-Stack Software Engineer for a fully remote contractor role based in Spain. You will work on an AI training project, tackling cross-language coding tasks and multi-language architectures.

The role emphasizes independent contribution, fast onboarding, and flexible hours around about 15 hours per week. You’ll develop across front-end and back-end systems, review AI-generated code, and ensure performance, security, and maintainability.

Qualifications

• Production-ready full-stack experience across web applications.
• Hands-on front-end and back-end proficiency in multiple languages.
• Strong understanding of APIs, state management, databases, and integrations.
• Ability to navigate unfamiliar codebases and evaluate architectures.
• Excellent debugging and analytical problem-solving skills.
• Available to contribute ~15 hours per week with flexible days.

Responsibilities

• Develop, modify, and debug front-end and back-end application components.
• Build user-facing features with supporting services and data models.
• Trace requests and data flows across browsers, APIs, and databases.
• Explore unfamiliar codebases and assess system interactions.
• Diagnose issues in authentication, persistence, networking, and deployment.
• Evaluate, improve, and validate code across languages.
• Review AI-generated solutions for quality, performance, and security.
• Translate complete coding implementations between languages as needed.
• Meet weekly task submission requirements and adhere to specs.

Skills

Full-stack development

Front-end & back-end

API integration

Debugging

Cross-language

Job description

Jobgether is seeking a Sr. Full-Stack Software Engineer for a fully remote contractor role based in Spain. You will work on an AI training project, tackling cross-language coding tasks and multi-language architectures.

The role emphasizes independent contribution, fast onboarding, and flexible hours around about 15 hours per week. You’ll develop across front-end and back-end systems, review AI-generated code, and ensure performance, security, and maintainability.