I'm Felix Tellmann

I'm a freelancing web developer, writer and entrepreneur living in Cape Town. I enjoy creating things that live on the internet, whether that be websites, applications, or anything in between. My goal is to always build products that provide real value to its users.

Recent Posts

Book Review: Hooked - Nir Eyal

Automatic behaviours triggered by situational cues: things we do with little or no conscious thought. Forming habits for products is imperative for its survival.

How to add color themes in ReactJS?

More than just dark-mode, add any number of color themes to your react site.

Exploring the React useEffect hook

Check out how the useEffect hook works.



A custom React Hook to help you implement styled system props in combination with styled-jsx for your application.


A custom React Hook to help you implement a "theming" classes for your application. The hook allows you to add as many color themes as you wish.

When and where


  • In-Progress

    Currently, I'm working on a online course focussing on holistic react applications with next.js

  • Launched my new website v3.0

    Finally after a few months of design & redesigns, and other projects in the background, I got my new page up and running.

  • use-styled-system & use-color-theme

    Created & published two custom react hooks as npm packages, and planning the next one.

  • New - Old - Beginnings

    Restarted my freelancing Web Development and got back in touch with clients.

  • When the world stopped

    From a successful restaurant to closing our doors in a matter of weeks. Its been a great journey, the uncertainty of corona and the national lockdown have clarified major life-changing questions. Answering them became easy overnight.

  • Best Season so far

    Grew the restaurant consistently, with the best season and a blast of a staff party to finish off the holiday times.


  • Data Analysis -> Smart-Up

    Used the restaurants sales & performance data to gather insights & to establish new training approaches for Smart-Up to use internally in the restaurant. Including a deep dive into MySQL & Oracle DB.

  • Restaurant v2.0

    Upgraded the concept to the fit market environment & changed the name from The Burger Exchange to The Exchange and shifted focus to also include a variety of woodfired grills. 🥩🔥

  • Visited Namibia

    Fulfilled a lifetime dream to 4x4 drive and camp in Namibia with the best friends.