Senior AI + MERN Stack Engineer | SaaS Development & AI

We are looking for a highly skilled Senior AI + MERN Stack Engineer to join our team and work on an existing SaaS product. The ideal candidate should have strong expertise in the MERN stack (MongoDB, Express.js, React.js, and Nde.js), along with hands-on experience building and integrating AI-powered solutions. You will be responsible for maintaining and improving our existing SaaS platform, developing new features, integrating AI capabilities, optimizing application performance, and ensuring scalability and reliability. We are looking for someone who can understand an existing codebase, take ownership of technical tasks, suggest improvements, and contribute to the long-term growth of our product. This is an ongoing opportunity for the right candidate, with the potential for a long-term collaboration. Detailed Job Description # Senior AI + MERN Stack Engineer – SaaS Product Development ## About the Role We are seeking an experienced AI + MERN Stack Engineer to help maintain, enhance, and expand our existing SaaS platform. Our product is actively evolving, and we need someone who can work with our existing architecture while building new features and integrating modern AI technologies. You will collaborate with our team to improve existing functionality, develop scalable backend services, enhance frontend experiences, and introduce intelligent AI-powered features. ## Key Responsibilities - Maintain, enhance, and troubleshoot our existing SaaS application. - Develop new features and functionalities using the MERN stack. - Build scalable and reusable frontend components using React.js. - Develop and maintain RESTful APIs using Node.js and Express.js. - Design, optimize, and manage MongoDB databases and schemas. - Integrate AI models, LLMs, and third-party AI APIs into the SaaS platform. - Develop AI-powered features using OpenAI, Anthropic, or other relevant AI technologies. - Work with prompt engineering, LLM workflows, and AI automation. - Implement AI-driven workflows, intelligent content processing, and automation where required. - Optimize application performance, security, scalability, and reliability. - Identify and resolve bugs, technical issues, and performance bottlenecks. - Write clean, maintainable, reusable, and well-documented code. - Participate in technical discussions and recommend architectural improvements. ## Required Technical Skills **MERN Stack** - Strong proficiency in MongoDB, Express.js, React.js, and Node.js. - Excellent JavaScript and TypeScript knowledge. - Experience developing REST APIs and backend services. - Strong understanding of frontend architecture and state management. - Experience with authentication, authorization, and secure API development. **AI & LLM Integration** - Hands-on experience integrating OpenAI APIs, GPT models, or Anthropic Claude. - Understanding of Large Language Models (LLMs) and prompt engineering. - Experience with AI-powered application development. - Familiarity with RAG (Retrieval-Augmented Generation), embeddings, and vector databases. - Experience with LangChain, LangGraph, or similar AI orchestration frameworks is a plus. - Understanding of AI agents, automation, and intelligent workflows. **SaaS & Engineering** - Experience working on production-level SaaS applications. - Understanding of multi-tenant SaaS architecture. - Experience with third-party API integrations. - Knowledge of cloud platforms such as AWS, Azure, or GCP. - Familiarity with Git, CI/CD pipelines, Docker, and deployment processes. - Strong debugging, problem-solving, and architectural skills. ## Nice to Have - Experience scaling existing SaaS products. - Experience with Redis, background jobs, and message queues. - Knowledge of microservices and event-driven architecture. - Experience with Stripe or other payment gateway integrations. - Experience with analytics, reporting, and automation features. - Familiarity with modern AI frameworks and emerging AI technologies. ## What We Expect - Ability to understand and work with an existing codebase. - Strong ownership and accountability. - Ability to work independently and deliver high-quality solutions. - Clear communication and regular progress updates. - Proactive approach to identifying problems and suggesting improvements. - Availability for ongoing development and long-term collaboration. ## Engagement This is an ongoing project with continuous maintenance, improvements, and new feature development. We are looking for a reliable senior engineer who can become a long-term technical contributor to our SaaS product. If you have strong MERN stack experience combined with practical AI/LLM integration expertise, we would love to hear from you!