Grzegorz Lisowski

Technical skills

• TypeScript / Node.js / NestJS — Primary stack for modern APIs and services
• React / Next.js — Product UIs and full-stack frontends
• Ruby on Rails — Long-running production backends and modernization
• Python / Go — AI pipelines, SDKs, and compliance tooling
• PostgreSQL / Redis / OpenSearch — Data, caching, and search infrastructure
• AI / RAG / LLM tooling — Document pipelines, embeddings, and tool calling
• AWS / Docker / Terraform — Cloud infrastructure and CI/CD
• E-Invoicing — KSeF, ZUGFeRD, Factur-X, and GOBL

Experience & key deliveries

Gliwice, Poland · Remote

• Technical leadership: led cross-functional engineering squads (3–5 developers) through the full SDLC, owning system architecture, technical discovery, and code reviews
• Legacy modernization: transitioned Rails 4.2 to 7.x, replaced Ember 1.4/CoffeeScript frontends with React and ES6, updated UI frameworks to Bootstrap 5
• AI document audit & procurement: multimodal RAG document pipelines (Python, NestJS) and automated vendor scoring for enterprise client applications
• International e-invoicing: compliance infrastructure for KSeF (Poland), ZUGFeRD (Germany), and Factur-X (France) across a microservices architecture
• GOBL (open source): core contributor to a Go SDK (275★) for standardized multi-country JSON e-invoicing workflows
• High-traffic SaaS: hotel management and e-learning platforms serving millions of users, including A/B experimentation frameworks
• Additional delivery: 10+ custom web, AR/VR (Unity/ARKit), and back-office platforms across Fintech, EdTech, and PropTech