Nikolai D.

Senior Full-Stack Engineer · AI Integration & Automation · AI Engineer 🚀 $300K+ earned · 107 jobs · 9,100+ hours · Top Rated Plus & Expert-Vetted (top 1%) I'm a Senior Full-Stack Engineer (Laravel / Vue / Nuxt / React / Next / Node / NestJS) with 12+ years of production experience in fintech, Web3, crypto, iGaming, SaaS, marketplaces and booking platforms. Two things I do: build systems that hold up under real traffic, and wire AI into them where it actually pays off. HOW I WORK WITH AI Claude Code and Cursor are my daily tools, not an experiment. I write custom skills for Claude Code and manage context across sessions, which means I get productive in an unfamiliar codebase in hours instead of days. What I don't delegate without review: business logic, security, and anything touching money. I read every diff and don't merge what I don't understand. The useful skill isn't prompting, it's knowing which suggestions to reject. AI work I take on: - LLM integration into existing products (OpenAI, Anthropic APIs) - RAG and semantic search over your own documents and data - Document extraction pipelines (invoices, contracts, scanned PDFs) with measurable accuracy, not guesswork - Local LLM deployment when data can't leave your perimeter - AI agents and workflow automation - Deciding what should NOT be AI: anything that must be reproducible stays in code WHAT I DO BEST - High-load backends and scalable APIs (REST / GraphQL / WebSockets) - Maintainable frontends with Vue 2/3, Nuxt, React, Next.js - State management: Pinia, Vuex, Zustand, Redux - Performance work with measured results: admin dashboard 60s → 2s, page loads under 1s - Payments and money: Stripe, PayPal, regional processors, crypto wallets. Idempotent webhooks, transaction state machines, daily reconciliation - Refactoring legacy code into clean, modular systems - Third-party API integrations, including the ones with bad documentation RESULTS FROM REAL PROJECTS - Admin dashboard from 60s to 2s: traced with EXPLAIN ANALYZE to N+1 queries on top of missing indexes - Page loads under 1s through caching and architectural changes - Mobile app shipped on Ionic over an existing Vue codebase, no rewrite, no duplicated logic - Localization across 22 languages automated from a week of manual work to about an hour - UI component system that cut dialog build time by ~40% and became the product standard - Sportsbook API with real-time odds over WebSockets, shipped in 2 weeks from a one-line brief TESTING & QUALITY - Frontend: Vitest, Jest, Playwright - Backend: Pest, PHPUnit - I build systems that are testable, not fragile SCALABILITY & DEVOPS - Docker, Kubernetes, horizontal scaling, queue workers - Load balancers, caching strategies, Redis - PostgreSQL and MySQL with real query optimization - AWS, DigitalOcean, Linux, CI/CD (GitHub Actions, GitLab CI, Jenkins) WHY CLIENTS KEEP ME - 107 completed commercial projects, many of them long-term - Full ownership: I take an unclear idea, ask the right questions, and ship it - I tell you when something is a bad idea before you pay for it - Remote since 2013, so distributed work is my default, not an adjustment I care about business results, clean code and long-term maintainability. If you need a senior engineer you can trust with production, let's talk 🤝