[ work; ]

Products I built over the last two years. Most were experiments or startups that have since closed, so some links are gone. The screenshots are real.

app.cuppa.cz

Cuppa landing page: a phone showing an English conversation with an AI tutor

AI English tutor

Cuppa. English through five-minute AI voice calls.

A friend brought the idea and I joined to build it. I wrote the whole product: the voice pipeline, the learning logic, the dashboards and the company accounts.

Role Sole developer in a small team
Built with Web app, PWA, OpenRouter, Gemini, speech-to-text and text-to-speech models
Status Closed beta. The landing page is live.

Live AI voice calls: speech to text, a language model and text to speech, streamed in chunks so replies start fast.
AI feedback after every conversation, with flashcards and exercises generated from your own mistakes.
Company accounts. An employer hands out a registration code and staff join their company's plan.
One dashboard, four views of the same data: student, teacher, company manager and admin.
Installable web app (PWA) with push notifications.

app.cuppa.cz →

basiliskcharts.com

Basilisk landing page: a snake eye over dark scales

Crypto charts & backtests

Basilisk. Charts and strategy backtests for Bitcoin and other crypto futures.

A charting and backtesting tool for Binance perpetual futures, built so test results include the costs that real trading has.

Role Solo project
Built with Web app, market data APIs, Hetzner
Status The site is online. The backend is switched off.

Backtests that include fees, slippage and funding rates.
Built on my research into market structure and price action.
Self-hosted on a Hetzner server, with its own domain and deployment.

basiliskcharts.com →

sim

SIMScreenshots coming soon

Instagram autopilot

SIM. An Instagram account that runs itself.

A tool that writes Instagram posts and publishes them on a schedule, so an account keeps posting without someone sitting behind it.

Role Solo project
Built with AI generation, scheduling, Instagram publishing
Status Retired.

Generates post text and visuals with AI.
Plans and publishes posts automatically.
Runs on its own once it is set up.

streamchair.com

Creator platform

Streamchair. Where creators post, stream and get paid.

My maturita project. A working social platform for content creators, and a full marketing and monetisation strategy for it.

Role Graduation project, solo
Built with JavaScript, Firebase Auth, Firestore, Firebase Storage
Status Defended in 2026.

Social feed, creator profiles, messages and rewards, on a working backend with accounts and file storage.
Written strategy: the 7P marketing mix, pricing and monetisation model, three competitors and a SWOT analysis.
Brand identity: logo, colours and type.

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Other projects

Constance

My own product brand, done entirely by me: brand identity, packaging design, the online shop, influencer collaborations, and packing and shipping orders through Zásilkovna.

Market data & neural networks

About a year and a half of research into market structure and price action. I wrote my own indicators and backtested strategies in Pine Script, then processed about a terabyte of market data on rented GPU servers and cloud storage to train a neural network that predicts crypto price moves.

Automations

Workflows in n8n, Make.com and Zapier. One of them ran a news account on X: every six hours it collected the latest news and posted a summary on its own.