CZ Dev (czaban.dev) is the software agency I co-founded with my brother Zsombor. The positioning: custom engineering for founders who’ve hit the ceiling of spreadsheets, Airtable, and no-code — and need something deliberate, typed, and maintained.
Division of labour
Both of us are full-stack. Zsombor leads the visual system — minimalist, architectural, craft-oriented. I did almost all of the frontend redesign on BEMER v2 inside that system, and I own the Python side across the portfolio: data modelling, business rules, backend workflows, automation, security, testing.
| Area | Owner |
|---|---|
| Python backend, data layer, Firebase, security, testing | Tamas (me) |
| Visual system, component language, TypeScript patterns | Zsombor |
| Frontend implementation (React, TypeScript) | Both — Tamas did most of BEMER v2 |
| Architecture, content, case studies | Both |
Public case studies
Listed at czaban.dev/portfolio, with longer writeups on this portfolio site:
| Project | What | Stack | Role |
|---|---|---|---|
| Vital Registry v1 | Production rental/sales CRM for a medical device business | Python, Streamlit, Firebase | Auth, navigation, 391-test suite |
| Vital Registry v2 | React rewrite of v1, live at vital-registry.com | React, TypeScript, Firebase | Data-layer port, multi-env deployment |
| KEV Explorer | Interactive dashboard over CISA’s 1,500+ Known Exploited Vulnerabilities | React, TypeScript, Recharts, GitHub Actions | Security data enrichment, EPSS scoring |
| Advisory Composer | Browser tool converting lockfiles into multi-channel security advisories | React, TypeScript, OSV.dev, EPSS | OSV query logic, formatter, Slack Block Kit |
Why “design-led”
Most small custom-software shops ship functional but visually unremarkable work. The pattern is to treat UI as an afterthought to the backend. CZ Dev flips that. Zsombor’s visual system comes first, and the backend is built to honour it. Every case study ships with considered typography, whitespace, and interaction design, not just a working feature set.
On v1 of BEMER the UX was what Streamlit allowed. On v2 I rebuilt most of the frontend inside Zsombor’s design system. The code is cleaner, the interactions are right for a mobile-first medical-device operator, and the production experience is a step-change from the v1 baseline.
Tech choices across the portfolio
- Frontend: React + TypeScript on every recent project. Component libraries we trust rather than building from scratch.
- Backend: Firebase for realtime-state apps (BEMER). Static + serverless where possible (KEV Explorer, Advisory Composer).
- Data sources: OSV.dev, CISA KEV feed, EPSS, NVD API v2 — public security data surfaced in interfaces defenders will actually use.
- Delivery: Multi-environment pipelines (dev/UAT/prod) on the production apps. GitHub Actions for nightly data refreshes on the public tools.
Status
Actively running. BEMER v2 is the first client in sustained production. KEV Explorer and Advisory Composer are public tools used as proof of what CZ Dev ships. I keep CZ Dev strictly out-of-hours alongside my full-time role.