Sergey K.

Hi, I'm Serhii - an orchestra man who will cover all your digital needs: from brand strategy and design to code, cloud, automation, and marketing funnels. I launch turnkey products that look great, work steadily, and grow faster than you can update your dashboard 📈.

What exactly do I do

• Development and architecture
  Flutter / React / Next.js, Node.js / Python / PHP / Go, WebRTC streaming, GraphQL, microservices, serverless, IoT (Raspberry Pi, Arduino), DevOps (Docker, Kubernetes, Terraform, CI/CD).

• eCommerce & CMS
  WooCommerce, OpenCart, Shopify, Magento, PrestaShop, BigCommerce, WordPress + ACF, Headless CMS (Strapi, Sanity), fast landing pages with PageSpeed 90+ and schema markup.

• UI/UX & Creative
  Design systems at Figma, Adobe (XD / PS / AI / AE), Webflow, 3D-graphics (Blender, Three.js), motion, brand identity, Behance case.

• Marketing and growth
  SEO/SEM, GA4, Hotjar, CRO, A/B tests, email marketing (Klaviyo, Mailchimp), PPC (Google Ads, Facebook Ads, TikTok Ads, LinkedIn Ads), ASO, AppsFlyer/Adjust, SMM strategies, content plans, Mixpanel/Amplitude analytics.

• Automation and AI
  Make (Integromat), n8n, Zapier, OpenAI / GPT-4, LangChain, RAG-systems, Telegram-bots, parsers, webhook-services, ML-models (TensorFlow, PyTorch).

• Business, product, and legal
  PERT assessments, Agile/Scrum, KPI/OKR, budgeting, risks, NDA/MSA/SLA reviews, GDPR/PCI-DSS, strategic workshops.

Why is it easy with me?

• All-in-one: one contact - full cycle. 

• Transparency: regular demos, sprints, and clear deadlines.

• Languages: 🇺🇦 Ukrainian, 🇬🇧 English. 

• Post-release support: monitoring, updates, optimisation.

📂 Where is my portfolio?

For confidentiality reasons, I deliberately do not publish cases in the public domain - it is too easy to copy the design or code. I show all the examples of work in private messages or on a call (NDA if necessary). Just write to me and I'll share the relevant projects upon your request.

Keywords: Flutter, Dart, React, React Native, Next.js, Angular, Vue, Node.js, Express, NestJS, Python, Django, FastAPI, PHP, Laravel, Symfony, Go, Rust, C++, Java, Kotlin, Swift, Objective‑C, C#, .NET, WebRTC, WebSockets, gRPC, GraphQL, REST API, Microservices, Serverless, AWS, GCP, Azure, DigitalOcean, Vercel, Netlify, Docker, Kubernetes, Helm, Terraform, Ansible, CI/CD, GitHub Actions, GitLab CI, Jenkins, Firebase, Firebase Remote Config, Firestore, Supabase, MySQL, PostgreSQL, MariaDB, MongoDB, DynamoDB, Redis, Elasticsearch, Stripe, PayPal, LiqPay, Fondy, Adyen, WooCommerce, OpenCart, Shopify, Magento, PrestaShop, BigCommerce, WordPress, ACF, Headless CMS, Webflow, Wix, Squarespace, SEO, SEM, PPC, Google Ads, Facebook Ads, TikTok Ads, LinkedIn Ads, CRO, A/B Testing, GA4, Mixpanel, Amplitude, Hotjar, AppsFlyer, Adjust, Branch, ASO, Email Marketing, Klaviyo, Mailchimp, HubSpot, SendGrid, Make.com, Integromat, n8n, Zapier, IFTTT, Power Automate, Webhooks, OpenAI, GPT‑4, Llama, LangChain, Pinecone, RAG, TensorFlow, PyTorch, HuggingFace, Stable Diffusion, Whisper, Three.js, Babylon.js, WebGL, React Three Fiber, Blender, Cinema 4D, Figma, Adobe XD, Photoshop, Illustrator, After Effects, Motion Design, 3D Modeling, UX Research, Wireframing, Prototyping, Design Systems, Branding, Storyboarding, Agile, Scrum, Kanban, PERT, OKR, KPI, Roadmapping, Risk Management, NDA, MSA, SLA, GDPR, CCPA, PCI‑DSS, Security, OAuth2, JWT, Pen Testing, Raspberry Pi, Arduino, ESP32, IoT, Automation, Data Visualization, Pandas, Matplotlib, Jest, Cypress, Playwright, Selenium, Postman, Copywriting, Content Writing, Ukrainian Translation, Polish Translation, Crypto, Blockchain, DeFi, NFT, Web Scraping, Data Engineering, ETL, Looker, Data Studio, Project Management, Stakeholder Management, Business Consulting.