Yanjun L.

Senior Full-Stack AI & SaaS Engineer | MVP Development | React&Python

🚀 Need to launch an AI-powered SaaS, build production-ready automations, or eliminate manual bottlenecks with secure infrastructure? "My objective is simple: Deliver clean, intelligent code that drives measurable business growth, not just complete a checklist." I am a Full-Stack Software Engineer specializing in backend architecture, AI/LLM integrations, high-performance APIs, and robust workflow automation. I help founders, scale-ups, and corporate teams transform technical concepts into high-converting digital products that run flawlessly under pressure. 💎 CORE SERVICES I DELIVER: ● AI & LLM Integration: Implementing intelligent features using OpenAI API, Claude (Anthropic), LangChain, and vector databases for custom chatbots, data extraction, and autonomous AI agents. ● SaaS & Web Application Development: Building scalable, secure web products from scratch using Python (FastAPI, Django), PHP (Laravel), and modern frontend frameworks like Vue.js. ● High-Performance API & System Integration: Connecting complex databases with third-party ecosystems (Stripe, HubSpot, Salesforce, custom CRMs) with strict adherence to data integrity. ● Intelligent Automation & Tooling: Developing custom Chrome Extensions for operational productivity, specialized internal scrapers, and automated workflows that save hundreds of engineering hours. 🛠️ TECHNICAL MATRIX: ● AI & Automation: OpenAI API, Claude API, LangChain, Prompt Engineering, Vector DBs ● Languages: Python, PHP, Golang, JavaScript, SQL ● Frameworks & Ecosystems: FastAPI, Django, Laravel, Vue.js, Node.js ● Cloud & Infrastructure: AWS, Vercel, Linux Server Administration, CI/CD pipelines 🔒 COMPLIANCE & PRIVACY ASSURANCE (For Enterprise Clients): As a professional engineer, I prioritize data protection, especially regarding AI data privacy and API security. All environments utilize secure credential management, strict IP assignment compliance, and robust data hygiene protocols. Non-Disclosure Agreements (NDAs) are welcome prior to project scoping. 🤝 WHY PARTNER WITH ME: ● Business-First Mindset: I prioritize the Lean MVP approach—getting your AI or SaaS product to market fast without over-engineering. ● Elite Debugging & Diagnostics: I specialize in "legacy code rescue"—turning unstable, broken, or undocumented systems into clean, maintainable assets. ● Transparent Communication: I break down complex architectural blockers into plain English, providing honest, realistic timelines. 📩 Facing a technical bottleneck or ready to build your next AI-driven micro-SaaS? Drop me a message below. Let’s get your infrastructure moving forward.