Dániel Kerekes

Full-stack engineer building web, mobile and desktop products.

Available now · Remote (CET) or on-site in Hungary

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About me

At a glance

Based in
Hungary
Languages
Hungarian, EnglishEnglish: proficient (C1) in writing, upper-intermediate (B2) in speaking, with a B2 language certificate.
Studied
BSc Computer Science

Technologies

Frontend
TypeScriptReactNext.jsAngularAstroTailwind CSSWebGL
Mobile
React NativeExpoFlutter
Backend
Node.jsNestJSPostgreSQLpgvectorConvexSupabaseStripe
AI
Vercel AI SDKClaude Agent SDKCodex SDKPython
Desktop
ElectronSwiftSwiftUI
Tooling
DockerGitHub ActionsCloudflareVitestPlaywrightSentry

Background

Feb 2025 - Oct 2026

Frontend, then Full-stack Developer

Leaf Software Development

Web, mobile and backend work for clients in sport, live events, retail and recruiting

2022 - 2026

BSc, Computer Science

University of Pécs

I build software the way I would want it built for me: carefully, and with the person on the other side of the screen in mind.

Selected work

A few products I built for clients, on the web and on mobile.

Also shipped

  • Dashboards coaches build themselves, from charts and metric cards they arrange and save
  • A press portal for a photo competition, with embargoed results and bulk photo downloads
  • An installable membership card that keeps working without a connection
  • A prize draw website I built end to end, from sign-in to invoice uploads, kept clear of bots
  • The admin panel and big-screen live results display behind a national photo competition
  • One-click PDF and Excel reports that coaches send straight from live analytics data
  • Push notifications and deep links that open the right screen every time
  • Translation tooling that keeps four app languages in sync from one spreadsheet, with no developer in the loop

Session replay that keeps up with hours of data

Sports analytics platform, web

Coaches replay a training session as it happened: every player moving across the pitch, in sync with the match video, with tools to measure distances and follow anyone on the field. I designed and built the replay, then rebuilt its playback so long sessions with many players stay smooth instead of freezing.

React, TypeScript, Canvas, Video sync

Paid plans for a local services marketplace

Local services marketplace, iOS and Android

Tradespeople on this app buy a paid plan that puts their profile up front. I built the whole purchase flow: the cart, checkout, the return to the app after paying, and what happens when a plan is suspended or runs out. I also added profile photo cropping, search history with smarter sorting, and push notifications that open the right screen.

Flutter, Bloc, Firebase, Deep links

Charts that redraw in a blink

Sports analytics platform, web

The main analytics charts slowed down as a team's data grew. I measured where the time went, moved rendering to the canvas and replaced one request per player with a single batched one. The numbers below come from before and after traces.

Chart update-82%

Before: 189 ms
After: 34 ms

Selection click-95%

Before: 610 ms
After: 32 ms

Reload after an edit-96%

Before: 3091 ms
After: 126 ms

React, Chart.js, Canvas, Profiling

A job board built to be found

Recruitment agency, web

One site replacing three, built to keep its place in search results: fast job search, landing pages for every city and category, structured data, sitemaps, and listings that expire on their own. I built it end to end on a headless CMS, with tests guarding the parts search depends on.

Next.js, Payload CMS, PostgreSQL, Playwright

A mobile app from first commit to release

Sports analytics companion app, iOS and Android

I built the coaches' mobile app from an empty repository: live session timing, team and athlete management, heatmaps and per-athlete summaries, sized for both phones and tablets. Automated end-to-end tests and a cloud build pipeline ship every release.

React Native, Expo, TypeScript, Maestro, EAS

Live voting for juries

Live events, iOS and Android

A tablet-friendly app jurors use to score entries in real time, from simple yes or no votes to full rankings, in four languages. I worked on its core voting flows, passwordless sign-in and the connection handling that keeps votes flowing when the network does not.

Flutter, WebSockets, Sentry

On my own time

Products I designed, built and shipped myself, and a few bigger ones still on the bench.

Shipped

  • VectisGitHub Actions, on the Mac you already own.
    The Vectis app showing running macOS and Ubuntu virtual machines and recent jobs.

    A Mac app that runs your CI jobs on your own machine, each in a fresh virtual machine that is thrown away afterwards. No rented runners, no leftovers between jobs.

    Website for VectisSource for Vectis
  • GradMateA study platform for university students.
    The GradMate dashboard with recent notes, subjects, weather and upcoming events.

    Everything a semester needs in one place: notes, a calendar and your course material, with an AI study partner that works only from your own notes. Privacy comes first, so notes are stored encrypted and accounts are protected with two-factor sign-in.

    • Notes you can write together in real time, with formulas and pasted documents
    • Summaries and practice tests generated from your own notes and PDFs
    • Suggestions that finish your sentence while you write
    • A calendar that helps plan exams and study time
    • Course recommendations based on what you study
    Website for GradMate
  • UpsterPut small apps from your computer online.
    The Upster dashboard listing small apps, most of them running on their own subdomains.

    One dashboard to put side projects, demos and small tools online on your own domain, straight from your computer, without renting or configuring a server. It runs as a desktop app or in Docker.

    • Publish an app to your own domain in a few clicks
    • Keys and tokens stay encrypted, even while you work
    • Reach the dashboard from your phone after pairing with a QR code
    • Freeze a version of a project and roll it out when you are ready
    • Let AI coding agents deploy with limited, short-lived access
    Source for Upster
  • InbotEmail inboxes for AI agents, kept on your machine.
    The Inbot mail view with an inbox per AI agent and a conversation one of them is handling.

    Gives every AI agent its own email address on your own domain. Mail is stored encrypted on your computer, not on someone else's server, and nothing goes out until you approve it.

    • An inbox for each agent, created and paused in a few clicks
    • Mail stays encrypted until it reaches your own machine
    • Drafts wait for your approval, or go out on a schedule
    • Allow and block lists decide who can reach your agents
    • Agents get limited keys instead of full access to your mail
    Website for InbotSource for Inbot
  • wdJump into any project with one command.

    A command-line tool that finds the project you are looking for and opens your whole workspace for it: editor, terminals and containers.

    Source for wd

In the workshop

  • MerinA private, fast browser for the Mac.In development

    Built on Chromium, so every site just works, with a native Mac interface around it. Nothing is sent home: no telemetry, no analytics, and your history, logins and downloads are encrypted on your Mac.

    • Tabs that sleep in the background and wake up exactly where you left them
    • Floating picture in picture for any video
    • Links that open in a quick preview without leaving the page
  • PlutonerA home base for running AI coding agents.In development

    Start, queue and follow coding agents across all your projects from one place that keeps working through crashes and restarts.

  • BonnieMy own take on Docker, built from scratch.Research

    A container engine that aims to run everyday Docker workflows with far less disk, memory and fuss.

Have something worth building?

Email is the quickest way to reach me.

hello@kerd.dev

© 2026 Dániel Kerekes

Based in Hungary