Open to collaboration

Jan Šťastka

Full Stack Developer

Software Integration Specialist

Software Engineer at R2B2 · Full Stack Developer focused on React architecture, ad tech infrastructure, and frontend performance.

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01 — About

A bit of context

I am a Full Stack Developer and Software Integration Specialist focused on frontend performance, React architecture, and ad tech infrastructure. Currently at R2B2 as a Software Engineer, I own React components and E2E tests, support custom web apps for AYM & Caroda, and drive platform merges. Previously at Avon for 3+ years, I built and published web platforms across CZ/SK markets, redesigned homepages, relaunched the customer club with Svelte, and automated export pipelines that cut a 2-day process down to 1 hour.

4+ Years of experience

2 Companies worked at

2 Languages spoken

BSc Information Technology

02 — Experience

Where I've been

May 2024 – Present R2B2 Ad monetization partner Praha · Full-time · Hybrid

Software Engineer

Responsibilities: Custom web app support (AYM & Caroda) · Ensuring ad script delivery and quality · Main owner of React components & E2E tests · Collaboration on platforms merge (R2B2 & Caroda).

Achievements: Finished ongoing redesign · Rework from React Table to TanStack Table · Replace drag & drop and date picker libraries · Upgrade React from v16 to v18 & prepare for v19 · Migration from Timescale to ClickHouse · Reduce ad delivery script size by ~10% gzip (~30% raw) · Automate ad placement creation in Caroda.

TypeScriptReactTanStackClickHousePlaywright

Sep 2022 – Apr 2024 Avon Praha · Full-time · Remote

Web Publisher

Responsibilities: Content controller of platforms (MAS CZ/SK) · Web publisher and frontend developer of MAS CZ/SK · Web optimization · Overseeing Content & Campaign setup for avon.cz, avon.sk · Creation of web pages.

Achievements: Built components for Avon's platforms (address validation, product carousel, promo code section) using HTML, CSS, JS, GTM, Dynamic Yield · Menu & small components on avon.cz · Anew product page · Valentyne's product page · Christmas gift finder.

HTMLCSSJavaScriptGTMDynamic Yield

Oct 2020 – Aug 2022 Avon Czechia · Part-time · Remote

Key Tester & Content Controller & Incidents Manager

Responsibilities: Content controller of platforms (MAB CZ, GI3 SK, NOEL CZ/SK, MAO CZ/SK) · UAT testing across avon.cz, avon.sk, AvonON app, Grow app, Digital brochure, Avon Rewards, Loyalty Club · Incidents management & PROD Smoke/Sanity tests · Participation in Digital Projects (MAB, GI3, MAO Avon Rewards, Grow web).

Achievements: Homepage redesign for avon.cz & avon.sk using HTML, CSS, JS · Customer club relaunch using Svelte · Innovation of processes — CSV export from 2 days to 1 hour, semi-automated product validation between platforms, user-friendly NOEL exports (JSON).

HTMLCSSJavaScriptSvelteUAT testing

03 — Projects

Selected work

Personal Portfolio

Jul 2026

This site. A self-hosted portfolio with a file-based CMS, built on SvelteKit and Svelte 5. Server-rendered, containerized, and deployed behind Caddy with automatic HTTPS.

SvelteKitSvelte 5TypeScriptSCSSDocker

Šťástka Autodoprava

Jan 2020 – May 2020

Full redesign of a WordPress-based website for a trucking company based in Liberec. Custom content, fleet overview, and basic SEO optimization.

WordPressHTMLCSSSEO

04 — Skills

Tools of the trade

Core stack

HTML

CSS

TypeScript

React

Svelte

Node.js

SQL

PHP

Playwright

Frontend

SASSResponzivní designUXWeb VitalsTechnické SEOGoogle Tag ManagerGoogle Search ConsoleVue.jsNuxtNext.js

Backend & Data

Express.jsREST APIGraphQLMySQLPostgreSQLMongoDBClickhouseDatové modelováníXMLJSONAJAXRegExp

Testing & Quality

PlaywrightCypress.ioJestUAT testováníAutomatizované testováníESLintPrettier

Tools & Platforms

GitNPMDockerAzure cloudWordPressFigmaJiraConfluenceTrelloAsanaJavaPython

05 — Languages

Across borders

Czech Native

English Professional

German Limited

06 — Contact

Let's build something together.

Whether you have a project in mind or just want to say hi — my inbox is always open.

jan.stastka12@gmail.com LinkedIn GitHub