zabolotny.de · Dresden, Germany AI products shipped live
🔨 Currently building: MeisterMeld

Serge
Zabolotny – Fullstack & AI Developer in Dresden

10+ Projects
7 AI products
B2+ German
View Projects → Download CV ↓
Serge Zabolotny
Available for Projects
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AI Integration✦Next.js✦FastAPI✦SvelteKit✦React✦OpenAI API✦Groq API✦Python✦PostgreSQL✦Telegram Bot✦WordPress✦Java Spring✦ AI Integration✦Next.js✦FastAPI✦SvelteKit✦React✦OpenAI API✦Groq API✦Python✦PostgreSQL✦Telegram Bot✦WordPress✦Java Spring✦
01 / About

I build AI products that solve real problems.

As an AI Fullstack Developer I specialize in intelligent web applications — from idea to deployment.

With experience as CTO and hands-on operations (CI/CD, VPS, Proxmox homelab), I deliver solutions that do not just run but are run reliably.

Based in Dresden. Open for full-time and freelance projects.

10+
Projects
2
Years full-stack
B2+
German 2025
4
Languages

Quick facts

Role
Fullstack & AI developer with a DevOps focus
Location
Dresden, Germany (remote possible)
Tech stack
TypeScript, Next.js, React, Python, FastAPI, PostgreSQL, Docker, GitHub Actions, Linux
Own products
MeisterMeld, PflegeOasis, ScamGuard
Experience
Since 2024 building own AI and web products from idea to operation; previously CTO (2011–2017); 960-hour Java web development training (DEKRA-certified)
Available for
Full-time roles (fullstack / DevOps / platform engineering) and freelance projects
02 / Skills
Frontend
Next.jsReactSvelteKitTypeScriptTailwind CSSJavaScript ES6+HTML5/CSS3Vite
Backend
PythonFastAPIJavaSpring BootREST APITelegram Bot APIaiogram 3
Databases
PostgreSQLMySQLSupabaseRedisGIN Index
AI & Integrations
OpenAI APIGroq APIPrompt EngineeringTesseract OCRGoogle Solar APIStripe
Cloud & DevOps
Linux VPSnginxsystemdDockerCloudflareGitHub ActionsVercelWordPressSEOProxmox VELXCHomelab / Bare-Metal
03 / Engineering Proof
AI Pipelines

From prompt to product

Vision/OCR, structured outputs, AI content pipelines with human review and multilingual generation inside real apps, not toy demos.

Backend & Data

APIs, jobs and subscriptions

FastAPI, PostgreSQL, Stripe, Telegram bots and clean data models for products that keep running.

Deployment

Self-hosted infrastructure

Multiple services behind nginx, systemd units, SSL, Cloudflare and monitoring — on VPS and my own Proxmox hardware with LXC containers.

Product Thinking

More than code

Landing pages, UX flows, local SEO, payment logic and MVP scope handled end to end.

Bonus · Homelab

My own server at home

What I do on VPS for work, I also run privately on my own hardware: virtualization, containers, networking, backups and monitoring — as a hobby and a training ground for production practices.

  • Proxmox VE on HP EliteDesk 800 G3 · 16 GB RAM · 1 TB NVMe, 512 GB SSD, 2 TB HDD
  • 4 LXC containers separated by role, 15+ self-hosted services in Docker
  • External access via Tailscale and Cloudflare Tunnel with Zero Trust Access
  • Daily vzdump backups to a separate disk, retention 7 days / 4 weeks / 3 months
  • Monitoring with Uptime Kuma and Glances, protection with Fail2ban and AdGuard DNS
  • Migrated all containers and media from SATA SSD to NVMe with pct move-volume

The series to rebuild it: Leaving the cloud · Proxmox & LXC · Access & backups

Homelab architecture Proxmox VE host with four LXC containers, reached via Cloudflare Tunnel and Tailscale; storage split into NVMe, SSD and a backup HDD. Cloudflare Tunnel + Access Tailscale (WireGuard) PROXMOX VE · HP ELITEDESK 800 G3 · 16 GB CT100 · dev-server Projects · PostgreSQL CT101 · home-media Nextcloud · Immich · Jellyfin Paperless · AdGuard · Fail2ban CT102 · smarthome Home Assistant · Frigate · MQTT CT103 · network-gateway Tailscale · Uptime Kuma Homepage NVMe 1 TB containers + media SSD 512 GB host OS HDD 2 TB daily vzdump backups
04 / Career
2026
DevOps practice & AI products
MeisterMeld and PflegeOasis live on my own VPS with CI/CD via GitHub Actions, plus ScamGuard. At home a Proxmox homelab with Tailscale and Cloudflare Zero Trust – operations, not just development.
2025
AI SaaS Developer
SolarCheck AI, MeisterMeld, DreamDeck — solo-built AI products from concept to production deployment on own VPS.
2024
AI Fullstack Developer
Smart-Letter, GeschenkFox, RenovAI — FastAPI + React/SvelteKit, Groq/OpenAI APIs, self-hosted VPS infrastructure.
2023
Professional training: Java Web Development — Starta Institut (Tel-Ran), Berlin
960h Java Web Development: Spring Boot, REST APIs, PostgreSQL, DevOps Basics. Graduation project: CRM system. DEKRA-certified.
2017
Technical Support — Germany
Teleperformance Görlitz (2017–2019): Apple support. 2019–2021: self-study in web development (JavaScript, React, Python). Concentrix Berlin (2021–2022): Facebook Business support.
2012
Web Developer & CTO — Ukraine
Built monetized websites on WordPress & DLE (contextual ads). CTO at MKP Gazkomplektprylad (2011–2017): tech leadership, process optimization, team coordination.
05 / Projects
11

MeisterMeld MVP live

Field service management for craftsmen: customer, job & employee management, PWA, AI reports, voice/photo uploads.

Solo development: Next.js, Drizzle ORM, PostgreSQL, PWA, AI integration, 1blu deployment

PWA for mobile teamsDrizzle ORM data modelDeployment on 1blu server
Next.jsTypeScriptDrizzle ORMPostgreSQLPWAAI Reports1blu
Live ↗
10

PflegeOasis.de MVP live

Free guidance portal for long-term care in Germany: care-level and care-allowance calculators, objection letter generator, application checklist and 200+ guide articles.

Concept and solo development: Next.js, data model, calculator logic, AI content pipeline, CI/CD and operations on own VPS

Care-level calculator based on the MD point system200+ articles: AI drafts with human reviewCI/CD: GitHub Actions → VPS (PM2 + Caddy)
Next.js 15TypeScriptTailwind CSSPostgreSQL 16Drizzle ORMOpenAI APIreact-pdf1blu VPS · PM2 · Caddy
Live ↗
09

ScamGuard MVP live

AI-powered platform that automatically analyzes job listings and messages for scam patterns — multilingual, with dedicated SSR routes per language and local browser history.

Solo development: Next.js App Router, multilingual SSR routes, AI classification, deployment on own VPS

Multilingual SSR routes ([lang])Real-time AI scam detectionHistory TTL in localStorage
Next.jsTypeScriptAI Classificationi18n SSRVPS · nginx · PM2
Live ↗
08

SolarCheck AI In Development

B2B lead platform for the solar industry: AI analyzes rooftop potential by address, calculates ROI using real electricity prices and KfW subsidies — and delivers qualified leads to solar installers.

Solo development: SvelteKit, FastAPI, Google Solar API, PostgreSQL, Stripe, VPS

Address-based solar analysisROI logic with external APIsB2B pay-per-lead model
SvelteKitFastAPIGoogle Solar APIPostgreSQLStripeClaude Vision
Website ↗
07

RenovAI In Development

AI analyzes room photos or floor plans and automatically generates a detailed cost estimate with works, materials, prices and design suggestions.

Solo development: React, FastAPI, PostgreSQL, OpenAI Vision, VPS deployment

Vision analysis of room photosStructured cost estimationFastAPI backend on VPS
ReactFastAPIPostgreSQLOpenAI VisionVPS
Website ↗
06

GeschenkFox.de MVP live

AI gift finder with interactive quiz for the German market. SEO-optimized architecture.

Solo implementation: Design (Figma), Frontend, SEO, UX concept

SEO-oriented SvelteKit architectureQuiz UX for purchase intentAI recommendation logic
SvelteKit + ViteTailwind CSSOpenAI APIVercel
Live ↗
05

DreamDeck MVP live

AI dream journal as a Telegram bot: dream analysis, emotion recognition, weekly insights and pattern detection.

Solo development: AI integration, Backend, Database, UX

Telegram bot with freemium flowPostgreSQL subscription trackingGroq API for fast replies
PythonTelegram BotGroq APIPostgreSQLaiogram
Bot ↗
04

Smart-Letter Archived

AI platform: professional letters in 17 languages, speech recognition, PDF/DOCX/JPEG processing.

Solo development: Architecture, Frontend, Backend, AI Integration

PDF/DOCX/JPEG processing17 languages in productionSource code on GitHub
FastAPIReact + ViteGroq APIPostgreSQLVercel
Code ↗
03

Kernbohr-Expert.de Completed

Corporate website for diamond core drilling. Local SEO, Google Maps, customer inquiries.

Solo development: Structure, Layout, local SEO strategy

WordPressSEOGoogle Maps
↗
02

Trockenbauservice-Salcutan.de Completed

Website for drywall construction company. Project gallery, customer reviews, mobile-first.

Solo implementation: Design, CMS integration, mobile optimization

WordPressCSS individuellPortfolio Plugin
↗
01

CRM System Thesis Project

Fullstack CRM: role management, project overview, reports. Graduation project.

Solo development: Database design, Backend, Frontend, API

Java Spring BootAngularMySQLREST API
↗
06 / Engineering Notes

Concrete problems, decisions and results from my projects — briefly noted.

Cloudflare · Zero Trust10/2026

Zero Trust instead of open dashboards

Problem An internal homelab dashboard was publicly reachable through a subdomain.

Reachable only with login
  • Cloudflare Tunnel as the only entry point — no port forwarding on the router
  • Access policy: only my email, login via one-time PIN
  • Private services exclusively via Tailscale
  • Lesson: regularly check what DNS and tunnels actually publish
Read the full note →
SEO · Build · i18n10/2026

Multilingual static pages without a framework

Problem Translations were swapped by JavaScript only — Google indexed German exclusively.

4 indexable language versions
  • Dependency-free Node script pre-renders /en/, /ru/, /ua/ from one source
  • hreflang, per-language canonical URLs and a sitemap with alternates
  • CI check fails when generated pages are out of date
  • Redirect only on an explicit language choice — crawlers always see German
View project →
Proxmox · LXC · Storage09/2026

Moving Proxmox to NVMe

Problem All containers lived on a SATA SSD, media on a constantly running USB HDD.

HDD now used for backups only
  • Moved root disks of all 4 LXC containers to an NVMe thin pool with pct move-volume
  • Media library on its own LVM volume, container bind mounts repointed
  • SMART check: the "new" NVMe was used — 33 TB written, but healthy
  • The HDD is touched only by the daily vzdump backup (7 / 4 / 3)
View project →
GitHub Actions · PM2 · Caddy2026

CI/CD for PflegeOasis

Problem Manual deployments to the VPS were slow and error-prone.

Deploy via git push
  • GitHub Actions → SSH → git pull, pnpm install, pnpm build
  • pm2 reload restarts the Next.js app without downtime
  • Caddy handles TLS certificates automatically
  • Next.js 15, PostgreSQL 16 and Drizzle ORM on a 1blu VPS
Read the full note →
OpenAI · Content · Review2026

AI content with human review

Problem 200+ guide articles on long-term care law — AI mistakes are not acceptable here.

200+ reviewed articles
  • OpenAI generates drafts offline — never live for users
  • Every article is reviewed by a human before publishing
  • Structured prompts with sources and legal basis
  • Lesson: on sensitive topics AI speeds things up, responsibility stays human
Read the full note →
FastAPI · Google Solar API05/2025

Google Solar API + B2B lead model

Problem Solar installers need qualified leads with realistic economics.

ROI from 4 data sources
  • Google Solar API returns roof area, kWp and kWh/year per address
  • FastAPI combines Open-Meteo, SMARD (BNetzA) and a KfW scraper
  • Stripe pay-per-lead for installers
  • Lesson: cache external APIs and handle outages gracefully
View project →
Cloudflare Workers · Edge04/2025

Cloudflare Worker as AI proxy

Problem The AI chat on this site needs an API key that must never reach the browser.

API key never in the browser
  • The chat widget talks to a Worker; only the Worker knows the Groq key
  • No own server, no cold start, global edge network
  • Single place for CORS and rate limiting
  • Try it live: "Ask AI about Serge" in the bottom right
FastAPI · Telegram · systemd03/2025

FastAPI microservice instead of no-code

Problem The contact form relied on n8n and Formspree — third parties for my own data.

No third-party form services
  • Own FastAPI endpoint validates input
  • Forwarding via the Telegram Bot API
  • Runs as a systemd service with auto-restart on my own VPS
  • Lesson: small own services are often simpler than no-code chains
nginx · systemd · VPS03/2025

From PaaS to my own VPS

Problem Projects were spread over Render, Netlify and Supabase — with limits and cold starts.

Several projects on one VPS
  • nginx as reverse proxy, SSL termination via Cloudflare
  • Each service as its own systemd unit with auto-restart
  • PostgreSQL and automated backups managed myself
  • Lesson: more control also means more responsibility for monitoring
Python · aiogram · Stripe02/2025

Freemium model for a Telegram bot

Problem DreamDeck should start free and unlock premium features via subscription.

Subscription logic in PostgreSQL
  • Stripe payments directly from the bot
  • Webhook instead of polling in production
  • Callback handler architecture with aiogram 3
  • Subscription status and limits modelled cleanly in PostgreSQL
View project →
OpenAI Vision · Structured Output01/2025

Vision API for document analysis

Problem Users upload letters as PDF, DOCX or photo — the content must be recognised reliably.

PDF · DOCX · JPEG → structured data
  • Text extraction with OpenAI Vision, including photos
  • Prompts for structured JSON output instead of free text
  • Built on top: reply letters in 17 languages (Smart-Letter)
  • Lesson: always validate outputs against a schema
View project →
Groq · OpenAI · LLM11/2024

Groq vs. OpenAI: speed vs. quality

Problem Real-time chat felt too slow with large models.

~10× faster replies
  • Fast open-source model via Groq for real-time chat
  • GPT-4o only for complex analysis
  • Hybrid routing lowers costs with the same UX
  • Update 10/2026: Llama 3.1 was shut down → switched to gpt-oss-20b. Lesson: keep the model ID in config, log API errors visibly
07 / References
"

Serge built two websites for my companies — Kernbohr-Expert.de and Trockenbauservice-Salcutan.de. Both are fast, mobile-optimized, and perform well in local search. Very structured approach, clear communication. Highly recommended.

IS
Ivan Salcutan
CEO · Kernbohr-Expert.de & Trockenbauservice-Salcutan.de
"

“[He was] a very competent employee who could be deployed anywhere. His behavior towards customers was above average and confident.”

Excerpt from the original job reference (English)

CX
Concentrix Global Services GmbH
Job Reference · Berlin · 2022
View reference (PDF)

Date of birth redacted for privacy

"

“Mr. Zabolotnyi has extensive professional knowledge. He contemplates difficult correlations, recognises what is essential and is able to quickly point out solutions. […] He always worked reliably and conscientiously.”

Excerpt from the English version of the reference (German original attached)

TP
Teleperformance Germany S. à r. l. & Co. KG
Employment Reference · Görlitz · 2019
View reference (PDF)

Date of birth redacted for privacy

08 / GitHub

Public code and commit activity — for anyone who likes to check things out before working together.

GitHub contribution graph — sergey-zabolotnyi
View GitHub profile →
09 / Contact

Let's build something together.

Open to full-time positions, freelance projects and AI development collaborations — in Dresden and remote.

For employers AI Fullstack Developer for production-minded teams
For clients AI MVPs, automations and web products end to end
Email click to reveal LinkedIn linkedin.com/in/szabolotnyi GitHub github.com/sergey-zabolotnyi Phone click to reveal

Your message goes straight to me — no third-party form services.

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