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Jan Schupke

Jan Schupke

Software Engineer

jan@schupke.io

Taipei, Taiwan

About

I'm a software engineer based in Taipei, with an academic background in computer science, networking, and security. For the last decade I have built products for B2B security and endpoint-management companies, marketing platforms, and advertising technology.

I take contracting work and build the whole product. That covers what your users see, whether it is a website, a web app, or a mobile or desktop client, and what sits behind it: servers, database, and integrations with the tools you already use. It also covers the less visible parts: reliable hosting, automated releases, monitoring that catches problems before your customers report them, and running costs that stay predictable as you grow. Where AI has a clear use in a workflow, I build that in as well.

Projects usually start with a conversation about what you need and a written scope, then get delivered in stages rather than all at once. For the technical detail, the Skills list covers the tools and platforms I use, and Showcase has the products I designed, built, and run myself.

For project scoping or contracting availability, email me at jan@schupke.io.

Background

Experience

Freelance, contracting, and own products

Taiwan / Global

Frontend developer

Finland

Frontend / fullstack developer

Czech Republic

Education

Bachelor's in networking and cybersecurity.

Languages

Czech, Slovak, English, Finnish.

Skills

Frontend

TypeScriptReactNext.jsTailwind CSSTanStack Queryi18n

Mobile

React NativeExpoMobile publishingApp Store / Play Console

Backend

Node.jsNestJSPrismaPostgreSQLSocket.IOREST APIs

Infrastructure

Docker / ComposeTerraformObject storage / S3GitHub ActionsVercelRenderAWS

Integrations

OpenAI APILangChain / LangGraphRAG systemsMCPOAuthClerkResend

Operations

Grafana stackOpenTelemetrySentryPostHogPino loggingPaddle

Testing

VitestJestPlaywrightReact Testing LibraryBraintrust evals

Showcase

Ceum helps solo freelancers keep the business side of work in order without turning into agency software. It covers time tracking, clients, projects, invoices, files, exports, and AI-assisted workflows over the same business data.

  • Time tracking
  • Income & expenses
  • Invoicing
  • Subscriptions
  • Clients & projects
  • Client mailing
  • Insights
  • Reports
  • Dashboard
  • Tasks & boards
  • Calendar
  • Alerts
  • MCP
  • CLI

Business Card Builder makes a business card you can print, send as a link, or hand over as a QR code, without an account. The whole card is encoded in the link, so nothing is stored on a server. Scanning it opens a page where every detail is tappable, and the same card downloads as a print-ready PDF, card images, or a contact file.

  • Two-sided card design
  • QR codes
  • Print-ready PDF
  • Card image export
  • Contact file
  • Shareable card page
  • No account

A personal app for writing and organising notes. Notes are stored in a folder structure, edited in Markdown, and kept in a private account.

  • Filesystem-like folder and note organisation
  • Markdown editor with rendered preview
  • Full-text search across notes

A self-study environment for the Linux command line, networking, and security tooling. Every exercise is solved by running real commands in a disposable Docker network, and the answer is checked instantly against the expected output.

  • 570+ exercises
  • 8 modules
  • Answer checking
  • Docker practice network
  • Progress & stats