Senior Full-Stack Developer for AI SaaS

CRIAVIA is an AI-powered SaaS platform that enables users to create websites, applications, and digital products using natural language. Our goal is to make software development accessible to everyone, starting with the Latin American market. We have an existing platform under development and are approaching launch. We're looking for an experienced, independent full-stack developer to take over technical development and help us scale. This is not a project starting from scratch. You will be joining an existing product and working directly with the founders. What you'll be working on - Take ownership of our existing codebase and development infrastructure. - Review the current architecture, identify technical issues, and recommend improvements. - Maintain and improve our AI-powered website and application builder. - Develop and optimize AI integrations, generation workflows, and APIs. - Improve the user experience, application performance, and platform stability. - Implement and maintain subscription billing, credit/token systems, and payment integrations. - Develop new features, fix bugs, and prepare the platform for production. - Maintain database integrations, authentication, and backend services. - Manage deployments, GitHub workflows, and production monitoring. - Collaborate with the founders on product development and technical planning. Technical requirements We're looking for someone with strong experience in: - Modern JavaScript/TypeScript and full-stack development. - React, Next.js, or comparable frontend frameworks. - Node.js, Python, or comparable backend technologies. - PostgreSQL, Supabase, or similar database solutions. - REST APIs, third-party integrations, and authentication. - AI APIs and LLM integrations (OpenAI, Anthropic, Google Gemini, etc.). - Cloud deployment, GitHub, CI/CD, and debugging. - Building and maintaining production SaaS applications. The technologies above represent relevant expertise. The developer must be comfortable working with our existing stack rather than requiring a rebuild. Highly desirable - Previous experience developing AI-powered SaaS products. - Experience with AI website builders, code-generation tools, or AI agents. - Experience integrating payment gateways and subscription systems. - Understanding of credit-based billing and AI usage tracking. - Experience optimizing LLM costs and performance. - Strong product thinking and ability to suggest improvements. - Experience working with early-stage startups. What we're looking for We don't want someone who only completes individual tasks. We're looking for a developer who understands the bigger picture, communicates clearly, takes responsibility for deliverables, and actively helps improve the product. You should be able to work independently, identify problems, propose solutions, and deliver reliable, maintainable code. What we offer - Long-term collaboration with an ambitious AI startup. - Direct communication with the founders. - Flexibility and remote work. - Opportunity to become our lead developer. - Consistent development work as the platform grows. - Potential for increased responsibilities based on performance. How to apply Please include: 1. Links to 2–3 SaaS platforms or AI products you've personally developed. 2. Your specific responsibilities in those projects. 3. Your experience with AI integrations or code-generation platforms. 4. Your availability and hourly rate. 5. A brief explanation of how you would approach taking over an existing SaaS codebase from another developer. We are particularly interested in developers who have built real products rather than only landing pages or basic AI chatbot integrations. We're looking to establish a serious, long-term working relationship with the right person.