Senior / Staff Frontend Engineer — since 2007

I build interfaces for data that refuses to sit still.

Drilling telemetry, European power grids, telemedicine, live video. Nineteen years of making heavy, real-time products feel instant — and leading the teams that build them.

Kraków, Poland

years in frontend
0
years in frontend
chart render latency
0s → 60ms
chart render latency
AI tools wired into one app
~0
AI tools wired into one app
published compiler research
IEEE
published compiler research

01 — Origin

2001

Lviv Polytechnic

Computer engineering, system programming. Algorithms, data structures — and the physical layer underneath them.

Lviv Polytechnic National University, main building
49.8353° N, 24.0144° E
EST. 1844 · LITTERIS ET ARTIBUS
2001→2007
Lviv Polytechnic National University, main building. Photo: Netmate, CC BY-SA 3.0

02 — Path

2007
2007–200901
Analytics

IOIX Ukraine

Frontend Engineer

Real-time visitor analytics platform; championed moving the corporate PHP engine to XHR/AJAX.

2009–201202
Web OS

ViaCube

Frontend Engineer

Components for a web-based operating system: presentation editor, file manager. Dojo, Comet.

2010–201503
Search & P2P

Archify GmbH / Freelance

Browser Extension Specialist

Privacy-first search engine (blippex.org): a WebRTC peer-to-peer client living inside browser extensions for 5 browsers, sharing anonymised data.

201304
Enterprise

SoftServe

Frontend Engineer

Calendar-based alert management utility for enterprise scheduling (ExtJS).

2013–201605
Fintech

EPAM Systems

Frontend Team Lead

Led an 8-person team on a fintech platform and a hotel booking system.

2016–202106
Live streaming

Hitbox Entertainment

Lead JS / Mobile Engineer

Cordova → React Native migration, native HLS modules, live trivia at scale.

2019–202307
EU power grid

ENTSO-E

Senior Frontend Engineer

Geospatial energy platform from scratch, TYNDP submission system, monorepo.

2023–202508
Telemedicine

Emmacare

Acting Tech Lead & FE Architect

Monorepo, security audit, WebRTC video, design-system theming.

2025–now09
Oil & gas IoT

Corva.ai

Senior Frontend Engineer

Drilling telemetry at 600k points: virtualization, workers, AI-driven architecture.

2026–now10
Civic data

kiedykarta.pl

Independent product

Real waiting times for Polish residence permits, built end to end.

2008201120142017202020232026
03 — Energy & Industrial IoT · Drilling

Corva.ai

Dec 2025 — present

Senior Frontend Engineer

Owner of data-heavy reporting apps: high-frequency drilling telemetry, processed and drawn with low latency for real-time monitoring.

  • Virtualized charts

    2.3s → 60ms — render latency

    Inherited a slow app and built a custom Highcharts windowing engine — O(1) instead of O(N) for 400k elements, with native scroll physics and cross-filtering intact.

  • Renderer-agnostic migration

    ~10s → <1s — worst-case freeze, 600k points

    After a WebGL prototype (SciChart, ~60 FPS) I distilled the findings into a spec — conversion → parsed model → renderer — with a 10-chart parity matrix and an 18-item pitfall catalogue, then drove the ECharts migration in a single AI-assisted session.

  • Architecture an AI can drive

    60 → 120 — AI tools

    Re-architected hard-coded behaviour into a configurable settings model the platform assistant can operate safely: single-write commands with read-back, stale-scope detection, undo baselines.

  • Depth ↔ time mapping

    O(log N) — event projection

    Coordinate mapping and data compaction for drilling time-series: prefix-sum indexing, piecewise linear interpolation and O(log N) binary search to project events onto non-linear axes.

  • TimeCompactor & filters

    40+ — filtering rules

    A fault-tolerant layer syncing malformed, non-contiguous data plus reactive filtering — 40+ business rules, cascades, interval merging — behind the most-used app in the ecosystem.

  • Off the main thread

    200k+ — records per export, no jank

    A Web Worker pool sized by hardwareConcurrency, zero-copy transfers and a sliding-window scheduler: no more UI freezes during 200k+ record exports.

  • 8,000 requests, tamed

    8,000+ — concurrent requests

    Re-engineered fetching with chunking, retries, aggregation and AbortController cancellation — a crash-prone bottleneck became stable.

QUATERNARYSHALESANDSTONELIMESTONERESERVOIRBASEMENTMEASURED DEPTH0 mROP m/hWOB klbfRPM rpmVIRTUAL WINDOWrendered 1,400 / 400,000 points · O(1)
StackReactTypeScriptHighchartsEChartsCanvasSVGSciChartWebGLTanStack QueryTanStack VirtualMUIWebSocketsWeb WorkersLLM tool-callingAbortController
04 — Healthcare & Telemedicine

Emmacare

Jul 2023 — Dec 2025

Senior FE Engineer · acting Tech Lead & FE Architect

Owned frontend architecture and technical decisions, working directly with the CEO and CTO through constant reprioritisation.

  • Two projects, one monorepo

    2–4× — faster feature migration

    Made the case for and executed the merge: unified Ant Design versions, TypeScript with a global typing system, React Query replacing legacy Redux.

  • Security audit

    XSS → CSP — hardened surface

    A proactive audit surfaced XSS vulnerabilities; introduced content sanitising, a CSP and JWT best practices.

  • Theming over BEM

    tokens — single source of style

    Replaced legacy BEM with theming on Ant Design tokens — long-standing CSS conflicts gone, design system finally feasible.

  • Real-time care

    WebRTC — video visits

    WebRTC video conferencing on Amazon Chime SDK, a themeable charting library on Recharts, scheduling on FullCalendar.

  • Team

    lead — architecture & people

    Mentoring on architecture, code reviews, interviews, onboarding, demos and estimation.

care-portal · visit #4821REC 12:47
Dr. M. · clinician
Patient
72
BPM
monorepo merge
clinician-apppatient-apppackages/*
antd v4+v5 → v5 · JS → TS · Redux → React Query
StackReactTypeScriptAnt DesignTanStack QueryRechartsFullCalendarAmazon Chime SDKWebRTCWebSocketsReduxSCSSpnpm monorepoWebpackFigmaXSS/CSP
05 — Energy & Utilities · EU Grid Infrastructure

ENTSO-E

Oct 2019 — Jul 2023

Senior Frontend Engineer

Platforms for the European network of transmission system operators: geospatial data, regulatory submissions and reports.

  • Geospatial platform, from scratch

    0 → 1 — built from scratch

    Architected a platform for geospatial and statistical energy data: API contracts, data structures, stack. Mapbox with custom data expressions and GeoJSON layers via turf.js; a Refine.dev admin panel.

  • Rescuing TYNDP

    AngularJS 1.2 — stabilised and extended

    Took over the Ten-Year Network Development Plan submission system on AngularJS 1.2 that previous vendors had left unmaintainable; refactored to components, opened a path to React, kept hard EU regulatory windows.

  • Reports without a backend

    PDF in workers — no duplicated logic

    One codebase shared across services, and client-side PDF generation with pdfMake inside Web Workers — mapping rendered data straight into reports.

  • Monorepo for the ecosystem

    1 — frontend ecosystem

    Shared libraries for ADFS/MSAL authentication, charting and geospatial components.

GeoJSON · Mapbox expressions
turf.buffer · turf.within
StackReactTypeScriptAngularJSMapboxturf.jsGeoJSONRefine.devAnt DesignNivoReact QuerypdfMakeWeb WorkersStorybookAzure DevOpsMSAL.jspnpm monorepo
06 — Live Streaming & Media

Hitbox Entertainment

Jan 2016 — Mar 2021

Lead JS / Mobile (React Native) Engineer

A high-traffic streaming platform competing with Twitch, plus a live trivia app competing with HQ Trivia.

  • Cordova → React Native

    RN — new mobile platform

    Proposed and led the migration of the mobile platform from Cordova/AngularJS to React Native — big gains in rendering performance and mobile UX.

  • Native HLS

    low-latency — ExoPlayer bridge

    Custom native modules bridging HLS playback through ExoPlayer on Android for low-latency video.

  • Live trivia at scale

    spikes — synced via HLS frames

    A real-time trivia app surviving massive concurrent spikes, synchronised through WebSockets and HLS data frames.

  • Streaming PWA

    PWA — offline + push

    React + Workbox progressive web app: one real-time streaming experience across browsers, offline support, push sync.

21:005G ▮▮▮
● LIVE👁 18,400
pro_streamer
Ranked · EU
Follow
nova POG that clutch
kr4ken stream is buttery on mobile now
mila 🔥🔥🔥
dzhe gg wp
xX_fr4g how is latency this low??
Send a message…
Cordova · AngularJS
24fps
StackReact NativeReactTypeScriptReduxExoPlayerAndroid SDKHLSChromecastApollo GraphQLJanus WebRTCWorkboxStyled Componentsi18nextReact-Admin

07 — Selected project

kiedykarta.pl↗

Oct 2026 — present · independent · live

~0k
public messages
0
community groups
~0
de-duplicated cases
WarszawaKrakówWrocławPoznańGdańsk

Share of cases still waiting

KM · 95% CI
0%25%50%75%100%090180270360days since filing

Illustrative Kaplan–Meier curve with confidence band

01

Data

A daily Node/TypeScript pipeline — scrape → rule-based multilingual parsing → case merging. Statistics stay honest on incomplete data: Kaplan–Meier ranges and low-sample flags.

02

Product

React + TanStack Start static prerender, custom SVG charts, offline-capable PWA; reader-submitted cases with passwordless sign-in (Telegram, Google, passkeys) on Cloudflare Functions + D1.

03

Delivery

GitHub Actions → Cloudflare Pages at near-zero cost. Privacy-first: pseudonymised data, cookieless analytics. Built with Claude Code — I owned the problem, domain rules and verification; the agent wrote code and tests.

0
prerendered pages
0
languages
0
automated tests
≈0
hosting cost
ReactTypeScriptTanStack StartViteNode.jsVitestGitHub ActionsCloudflare PagesD1PWAd3-geoClaude Code
Visit kiedykarta.pl ↗
React✦TypeScript✦WebGL✦Web Workers✦ECharts✦Highcharts✦Mapbox✦WebRTC✦React Native✦TanStack✦React✦TypeScript✦WebGL✦Web Workers✦ECharts✦Highcharts✦Mapbox✦WebRTC✦React Native✦TanStack✦
Canvas✦GeoJSON✦HLS✦PWA✦Node.js✦GraphQL✦WebSockets✦Claude Code✦d3-geo✦Vite✦Canvas✦GeoJSON✦HLS✦PWA✦Node.js✦GraphQL✦WebSockets✦Claude Code✦d3-geo✦Vite✦

08 — Stack

Languages & frameworks

05
  • React
  • TypeScript
  • JavaScript (ES6+)
  • React Native
  • Node.js

Architecture

09
  • Monorepos (pnpm, Webpack)
  • SSG / prerendering
  • PWA & service workers
  • TanStack Query
  • Zustand
  • REST
  • GraphQL
  • WebSockets
  • WebRTC

Data visualization

10
  • ECharts
  • Highcharts
  • SciChart (WebGL/WebGPU)
  • Custom SVG
  • Mapbox
  • d3-geo
  • turf.js
  • Nivo
  • Recharts
  • FullCalendar

Performance

06
  • Custom virtualization
  • Web Workers, zero-copy
  • Canvas / WebGL
  • Code splitting
  • Bundle optimization
  • Binary search, prefix sums

UI systems

07
  • Ant Design
  • MUI
  • Refine.dev
  • Styled Components
  • SCSS
  • Figma
  • Storybook

Security & quality

06
  • XSS/CSP audits
  • Sanitizing
  • JWT best practices
  • Jest
  • Vitest
  • React Testing Library

CI/CD & infra

03
  • GitHub Actions
  • Cloudflare Pages / Functions
  • Azure DevOps

AI-assisted engineering

04
  • Spec-driven agent workflows
  • Claude Code
  • Cursor
  • LLM tool-calling
DomainsEnergyOil & gasHealthcareLive streamingFintech