Full Stack Engineer

Cosmoxyn is a boutique, AI-first agency helping forward-thinking businesses build intelligent products. From custom AI/ML solutions and automation to modern web and mobile applications, we ship production-grade software that blends solid engineering with the latest in AI. We're a small, fast-moving team where your work directly shapes client outcomes.

We're looking for a Full Stack Engineer who is comfortable owning features end to end — from database schema to polished UI. You'll work across multiple client projects, building web applications with React/Next.js on the front end and Node.js on the back end, often integrating AI capabilities (LLM APIs, RAG pipelines, automation workflows) along the way.

• Design, build, and ship full stack features across client projects using Next.js, React, and Node.js
• Build and consume REST/GraphQL APIs; model data in SQL (MySQL/Postgres) and NoSQL databases
• Integrate third-party services and AI APIs (OpenAI, Anthropic, AWS Bedrock) into production applications
• Deploy and maintain applications on AWS (EC2, S3, Lambda, RDS); write clean CI/CD pipelines
• Collaborate directly with clients and internal stakeholders to translate requirements into technical solutions
• Write maintainable, well-tested code and participate in code reviews
• Contribute to architecture decisions and technical estimates for new engagements

• 3–6 years of professional full stack development experience
• Strong proficiency in JavaScript/TypeScript, React, and Node.js
• Hands-on experience with Next.js (App Router preferred) and modern frontend tooling
• Solid understanding of relational databases, API design, and authentication patterns
• Experience deploying and operating applications on AWS or similar cloud platforms
• Ability to work independently, manage priorities across projects, and communicate clearly in English
• A pragmatic, product-minded approach — you care about shipping value, not just writing code

• Experience integrating LLM APIs, building RAG systems, or working with vector databases
• Familiarity with Python for scripting or ML workflows
• Exposure to Docker, serverless architectures, or infrastructure-as-code
• Prior agency or client-facing consulting experience
• Open-source contributions or a portfolio of shipped side projects