# Jiří Zachar / zaachi.com

Jiří Zachar is a Software Engineer focused on end-to-end software engineering: complex systems, web applications, native mobile apps for iOS and Android, data, AI/LLM integrations and production infrastructure.

## Core capabilities
- Software architecture and large systems
- Web/backend: PHP, Nette Framework, Composer, Node.js, TypeScript, REST APIs, WebSockets
- Native mobile apps: Swift/SwiftUI for iOS, Kotlin/Jetpack Compose for Android, push notifications, Firebase, geolocation, authentication, App Store and Google Play delivery
- Data: PostgreSQL, MySQL, Microsoft SQL Server, Redis, query tuning and caching
- AI/LLM: OpenAI API, structured outputs, embeddings, RAG, semantic search, extraction, classification and automation
- Infrastructure: Docker, Debian/Linux, Apache/reverse proxy, SSL, monitoring, backups, recovery, self-hosting and load distribution
- Integrations, ERP, legacy modernization, OCR/document workflows and automation

Jiří can independently design, build, deploy and operate large technical systems, and has experience with both startups and enterprise environments as well as products used by people every day.

## Contact
Phone / WhatsApp: +420 608 836 498
LinkedIn: https://www.linkedin.com/in/zaachi/

## Language versions
- Czech: https://zaachi.com/cs/
- English: https://zaachi.com/en/

## Selected work
Jiří has worked end to end on enterprise digitalization platforms, native mobile/community products, and data/integration systems involving GPS/IoT-style workloads, APIs, databases, caching, background processing, production infrastructure and scaling. Some projects are presented without client names; specific references and additional project context can be shared when discussing a potential collaboration.