Md. Hasnat B.

With 10+ years of experience, I help startups and clients design scalable SaaS backends (Laravel, Node.js/NestJS, PostgreSQL) and embed production-grade AI features (LLMs, RAG, agentic workflows). Focused on shipping smarter, more automated products while keeping reliability and maintainability first, and comfortable owning system architecture, complex business logic (inventory, approvals, ledgers), and AI integration end-to-end. 🚀 𝗖𝗼𝗿𝗲 𝗘𝘅𝗽𝗲𝗿𝘁𝗶𝘀𝗲 ➤ SaaS products with multi-tenant, isolated-schema architecture ➤ B2B ordering, inventory, partner portals, and loyalty/points systems ➤ Marketplace and social platform backend systems (feeds, chat, moderation, ads) ➤ POS, shop management, credit ledger (khata), purchasing, returns, and reporting ➤ Business process automation and AI-assisted workflows ➤ AI integration: LLM APIs, RAG over docs/DB, agentic workflows, content moderation ➤ Dashboards, admin panels, and internal tools (Filament, React, Next.js, Vue) 🧠 𝗛𝗼𝘄 𝗜 𝗖𝗮𝗻 𝗛𝗲𝗹𝗽 𝗬𝗼𝘂 Whether you're launching an MVP or scaling an existing product: ✅ Design and build your SaaS or MVP from scratch with a clear, scalable architecture ✅ Integrate AI features: RAG Q&A, AI assistants, agentic workflows, summarization, classification ✅ Automate repetitive workflows using AI + backend jobs/queues (support triage, ticket routing, reports) ✅ Improve performance and scalability of an existing system without a full rewrite ✅ Own the full stack when you want one senior engineer responsible for backend, frontend, and AI 📁 𝗣𝗿𝗼𝗷𝗲𝗰𝘁 𝗘𝘅𝗽𝗲𝗿𝗶𝗲𝗻𝗰𝗲 𝗕2𝗕 𝗣𝗮𝗿𝘁𝗻𝗲𝗿 𝗣𝗼𝗿𝘁𝗮𝗹 — Laravel, Filament, PostgreSQL Built a global partner ordering and inventory platform with multi-level approvals, FIFO stock allocation (row-locking), loyalty/points ledger, and 380+ automated tests with CI. 𝗦𝗼𝗰𝗶𝗮𝗹 𝗖𝗼𝗺𝗺𝘂𝗻𝗶𝘁𝘆 & 𝗠𝗮𝗿𝗸𝗲𝘁𝗽𝗹𝗮𝗰𝗲 — Laravel, Octane, ClickHouse, Redis Backend for a large-scale social/marketplace platform with realtime messaging, feeds, stories, marketplace listings, ads, and layered trust/safety + AI content moderation; versioned OpenAPI mobile APIs and 1,300+ tests. 𝗢𝗿𝗱𝗿𝘆 — 𝗦𝗵𝗼𝗽 𝗠𝗮𝗻𝗮𝗴𝗲𝗺𝗲𝗻𝘁, 𝗣𝗢𝗦 & 𝗔𝗜 𝗔𝘀𝘀𝗶𝘀𝘁𝗮𝗻𝘁 — NestJS, TypeScript, React, PostgreSQL DDD/CQRS modular monolith for POS, khata ledger, multi-warehouse batch inventory, purchasing, returns, invoices, and FIFO-costed P&L; secure LLM shop assistant with read-only tool calling, JSONB RAG, SSE streaming, and RBAC. 𝗙𝗿𝗲𝗲𝗹𝗮𝗻𝗰𝗲 𝗪𝗼𝗿𝗱𝗣𝗿𝗲𝘀𝘀 & 𝗪𝗲𝗯 50+ custom WordPress/static sites with bespoke themes/plugins, WooCommerce, MemberPress, performance/SEO improvements, and responsive UIs. 🛠️ 𝗧𝗲𝗰𝗵 𝗦𝘁𝗮𝗰𝗸 Backend: PHP, Laravel, Node.js, NestJS, Express, REST API, OpenAPI, Queues, BullMQ, Multi-Tenant SaaS Frontend: JavaScript, TypeScript, React, Vue, Tailwind, PWA, Capacitor Databases & Search: PostgreSQL, MySQL, Redis, MongoDB, ClickHouse, JSONB, MeiliSearch, Algolia Architecture: SOLID, DDD, CQRS, Event-Driven, Modular Monoliths, Repository/Service Layers Security & Reliability: RBAC, JWT/OAuth/SSO, Rate Limiting, OWASP, Audit Logging, Observability Real-Time & Integrations: WebSockets, Redis Streams, FCM, AWS S3, Stripe, PayPal, Shopify Testing & DevOps: PHPUnit, Jest, Vitest, GitHub Actions, Docker, AWS, GCP, Digital Ocean, Cloudflare, CI/CD AI & Automation: AI Integration, AI Agents, LLM Tool Calling, RAG, Vector Search, Prompt Optimization 🏆 𝗪𝗵𝘆 𝗪𝗼𝗿𝗸 𝗪𝗶𝘁𝗵 𝗠𝗲 ➤ 10+ years building production web platforms and SaaS products ➤ Strong focus on system architecture, data integrity, and long-term maintainability ➤ Comfortable with complex domains: inventory, approvals, ledgers, multi-tenant SaaS ➤ Production-grade AI integration (LLMs, RAG, agents) instead of toy demos ➤ Clear communication, realistic timelines, and honest trade-off discussions 🤝 𝗟𝗲𝘁'𝘀 𝗪𝗼𝗿𝗸 𝗧𝗼𝗴𝗲𝘁𝗵𝗲𝗿 If you're looking for a senior backend & AI integration engineer who understands both the technical and business side, send me a message with what you're building, your stack, and where you want AI to help. I'll reply with a brief assessment and next step.