Sergei C.

𝗜 𝗯𝘂𝗶𝗹𝗱 𝗦𝗮𝗮𝗦 & 𝗔𝗜 𝗽𝗿𝗼𝗱𝘂𝗰𝘁𝘀 — 𝗳𝗿𝗼𝗺 𝗶𝗱𝗲𝗮 𝘁𝗼 𝗽𝗿𝗼𝗱𝘂𝗰𝘁𝗶𝗼𝗻 𝗮𝗻𝗱 𝘀𝗰𝗮𝗹𝗲. I'm Sergei, a hands-on SaaS architect, senior full-stack engineer, and technical lead with 10+ years of software development experience. I help founders and businesses turn ideas into working products, launch MVPs and POCs quickly, and evolve them into reliable, scalable platforms. 𝗜 𝗰𝗮𝗻 𝗱𝗲𝘀𝗶𝗴𝗻 𝗮𝗻𝗱 𝗯𝘂𝗶𝗹𝗱 𝘆𝗼𝘂𝗿 𝗽𝗿𝗼𝗱𝘂𝗰𝘁 𝗽𝗲𝗿𝘀𝗼𝗻𝗮𝗹𝗹𝘆 — 𝗼𝗿 𝗹𝗲𝗮𝗱 𝗮 𝘀𝗺𝗮𝗹𝗹 𝘁𝗲𝗮𝗺 𝗼𝗳 𝘀𝗲𝗻𝗶𝗼𝗿 𝗲𝗻𝗴𝗶𝗻𝗲𝗲𝗿𝘀 𝘄𝗵𝗲𝗻 𝘁𝗵𝗲 𝘀𝗰𝗼𝗽𝗲 𝗿𝗲𝗾𝘂𝗶𝗿𝗲𝘀 𝗶𝘁. You work directly with the person making technical decisions, writing code, reviewing architecture, and taking responsibility for delivery. My approach combines three things: → Senior-level software architecture and engineering → AI-assisted development and coding agents for faster execution → A proven engineering team when parallel development is needed 𝗪𝗛𝗔𝗧 𝗜 𝗖𝗔𝗡 𝗛𝗘𝗟𝗣 𝗬𝗢𝗨 𝗕𝗨𝗜𝗟𝗗 ◆ 𝗦𝗮𝗮𝗦 𝗣𝗹𝗮𝘁𝗳𝗼𝗿𝗺𝘀 & 𝗠𝗩𝗣 𝗗𝗲𝘃𝗲𝗹𝗼𝗽𝗺𝗲𝗻𝘁 • B2B SaaS, multi-tenant platforms and SaaS MVPs • CRM, ERP, marketplaces and workflow applications • Authentication, RBAC, tenant isolation and subscriptions • Stripe Billing, Connect, webhooks and API integrations ◆ 𝗔𝗜 𝗣𝗿𝗼𝗱𝘂𝗰𝘁𝘀 & 𝗜𝗻𝘁𝗲𝗴𝗿𝗮𝘁𝗶𝗼𝗻𝘀 • AI-powered SaaS applications and assistants • LLM integrations with OpenAI, Claude and other models • RAG, semantic search and document intelligence • AI agents, automation and tool-based workflows ◆ 𝗔𝗿𝗰𝗵𝗶𝘁𝗲𝗰𝘁𝘂𝗿𝗲, 𝗠𝗼𝗱𝗲𝗿𝗻𝗶𝘇𝗮𝘁𝗶𝗼𝗻 & 𝗦𝗰𝗮𝗹𝗶𝗻𝗴 • Software architecture and technical discovery • Legacy SaaS modernization and codebase rescue • Performance, security and production readiness • Cloud infrastructure, CI/CD and scalable backend systems 𝗧𝗪𝗢 𝗪𝗔𝗬𝗦 𝗜 𝗗𝗘𝗟𝗜𝗩𝗘𝗥 𝟭. 𝗥𝗮𝗽𝗶𝗱 𝗠𝗩𝗣 & 𝗣𝗢𝗖 𝗗𝗲𝘃𝗲𝗹𝗼𝗽𝗺𝗲𝗻𝘁 Need to validate an idea, launch a prototype, or demonstrate a working product quickly? I use modern AI coding agents and AI-assisted engineering workflows to accelerate implementation, testing, and iteration. I personally handle architecture, critical technical decisions, code reviews, and quality control. The goal is to move fast without creating a codebase you'll need to throw away after validation. 𝟮. 𝗣𝗿𝗼𝗱𝘂𝗰𝘁𝗶𝗼𝗻 𝗘𝗻𝗴𝗶𝗻𝗲𝗲𝗿𝗶𝗻𝗴 & 𝗟𝗼𝗻𝗴-𝗧𝗲𝗿𝗺 𝗗𝗲𝘃𝗲𝗹𝗼𝗽𝗺𝗲𝗻𝘁 For larger products, I lead AI-accelerated senior developers working across frontend, backend, infrastructure, and integrations. I remain your technical point of contact and take responsibility for architecture, engineering standards, code quality, and delivery. We build for real users, real business workflows, and long-term maintainability — not just a successful demo. 𝗔𝗜 𝗵𝗲𝗹𝗽𝘀 𝘂𝘀 𝘄𝗿𝗶𝘁𝗲 𝗰𝗼𝗱𝗲 𝗳𝗮𝘀𝘁𝗲𝗿. 𝗘𝗻𝗴𝗶𝗻𝗲𝗲𝗿𝗶𝗻𝗴 𝗲𝘅𝗽𝗲𝗿𝗶𝗲𝗻𝗰𝗲 𝗱𝗲𝘁𝗲𝗿𝗺𝗶𝗻𝗲𝘀 𝘄𝗵𝗲𝘁𝗵𝗲𝗿 𝘁𝗵𝗮𝘁 𝗰𝗼𝗱𝗲 𝗯𝗲𝗹𝗼𝗻𝗴𝘀 𝗶𝗻 𝗽𝗿𝗼𝗱𝘂𝗰𝘁𝗶𝗼𝗻. 𝗧𝗘𝗖𝗛 𝗦𝗧𝗔𝗖𝗞 ◆ Backend: Python, FastAPI, Node.js, NestJS, Laravel, PHP ◆ Frontend: React, Next.js, TypeScript, Vue.js, Tailwind CSS ◆ AI: OpenAI API, Claude, LLMs, AI Agents, RAG, LangChain ◆ Data: PostgreSQL, MySQL, Redis, Supabase ◆ Integrations: Stripe, REST API, GraphQL, OAuth, Webhooks ◆ Infrastructure: AWS, GCP, Docker, CI/CD ◆ AI Development: Claude Code, Codex, Cursor 𝗣𝗥𝗢𝗩𝗘𝗡 𝗧𝗥𝗔𝗖𝗞 𝗥𝗘𝗖𝗢𝗥𝗗 ◆ $1.9M+ earned on Upwork | 100% Job Success ◆ $1.4M+ from one B2B SaaS client over 7+ years of continuous development ◆ 10+ years building and maintaining software products ◆ 20+ projects across SaaS, business platforms and AI applications I know what it takes to build a product from scratch — and what it takes to keep it running and evolving for years. 𝗛𝗢𝗪 𝗪𝗘 𝗖𝗔𝗡 𝗦𝗧𝗔𝗥𝗧 - 𝗧𝗲𝗰𝗵𝗻𝗶𝗰𝗮𝗹 𝗗𝗶𝘀𝗰𝗼𝘃𝗲𝗿𝘆 / 𝗔𝗿𝗰𝗵𝗶𝘁𝗲𝗰𝘁𝘂𝗿𝗲 𝗥𝗲𝘃𝗶𝗲𝘄 — clarify scope, evaluate risks, define architecture and establish a realistic implementation plan. - 𝗠𝗩𝗣 / 𝗣𝗢𝗖 𝗦𝗽𝗿𝗶𝗻𝘁 — rapidly turn a defined idea into a working product or proof of concept. - 𝗢𝗻𝗴𝗼𝗶𝗻𝗴 𝗗𝗲𝘃𝗲𝗹𝗼𝗽𝗺𝗲𝗻𝘁 — work directly with me or with a senior engineering team under my technical leadership. 𝗟𝗘𝗧'𝗦 𝗕𝗨𝗜𝗟𝗗 𝗦𝗢𝗠𝗘𝗧𝗛𝗜𝗡𝗚 𝗧𝗛𝗔𝗧 𝗟𝗔𝗦𝗧𝗦 Whether you're starting from an idea, accelerating an existing MVP, or scaling a production SaaS platform, I can help you make the right technical decisions and execute them. Send me a short description of your product, current stage, and biggest challenge. 𝗬𝗼𝘂'𝗹𝗹 𝘀𝗽𝗲𝗮𝗸 𝗱𝗶𝗿𝗲𝗰𝘁𝗹𝘆 𝘄𝗶𝘁𝗵 𝘁𝗵𝗲 𝗲𝗻𝗴𝗶𝗻𝗲𝗲𝗿 𝗿𝗲𝘀𝗽𝗼𝗻𝘀𝗶𝗯𝗹𝗲 𝗳𝗼𝗿 𝗯𝘂𝗶𝗹𝗱𝗶𝗻𝗴 𝗶𝘁.