Friedrich Ewald My Personal Website


This list contains a selection of the projects I have worked on and I am currently working on. The most recent project is on top. Some of these projects are created out of curiosity to try out new techniques, languages or frameworks. Other projects are “small bets” where I am trying out different business ideas how they play out in the real world. If they are successful - by a metric of my choosing - I am planning to invest more into those. With this strategy, I hope to spend only a short amount of my free time on those projects and learn whether they are viable and attract an audience, before moving on to the next one.

Every Podcast Page

Small Bet - 2022

I wrote the first version of it in Python (Django) in 2021 during an extended holiday. It contained a lot of features (search, custom feeds, user profiles, etc.). However, those features made hosting this prohibitively expensive. In 2022, I decided to give it another try and rewrite the core application in Ruby (Rails). As a backend I use Sidekiq and Postgresql. One of the approaches I chose, was to also use the full-text search capabilities of PostgreSQL.

Screenshot of the front page of

The data for the directory is mostly scraped from the web via self written scrapers. If you like podcasts, you can check Every Podcast out here. If you have any ideas for additional features, please let me know.

hermes - iMessage analytics & exporting

Private Project - 2022

A command line interface written in Go for analysis and export of messages from the local iMessage database on MacOS. This project is hosted on my personal Github account. I got the idea from a Miranda IM plugin that I was using several years back.

Screenshot of the hermes CLI

Writic Code Interviews

Private Project - 2019

Platform for real-time collaboration and codeing interviews. I created this mostly because I was curious to learn how hard it is to implement a real-time collaboration editor and because we needed a platform for coding interviews at Zepl. As of today, the website allows you to register an account, gives a free trial and enables you to create real-time code editors that you can share via link. It is very similar albeit much more limited to Coderpad.

Writic landing page screenshot

Microblogging Platform

Private Project - 2019 (discontinued)

Another side project. I believe that many social networks share too much information and encourage posting of private details of everyone’s lives. On the other side these websites allow users to keep a lot of precious memories and moments. I am building this to provide a place for this kind of information: Memories that I want to keep, either in written form or as photos, but not necessarily share with the rest of the world.

Air Quality Index (AQI) Notifier

Private Project - 2018 (discontinued)

A side project based on Python/Django, the AirNow, Telegram and Twilio API. This tool allows to enter phone numbers or to self register via a telegram bot to receive updates about the air quality in your zip code once the quality significantly changes. I built this service to be informed about sudden changes of air quality after the massive wildfires in California in 2017 and 2018. In the most recent months, I have added more features:

  • Notification Threshold: This keeps you informed whenever the air quality index rises above a certain individual threshold. This is mostly to avoid spamming and only show really important changes in pollution.
  • Monitor air quality and temperature at home: Check it out here

Base62 Decoder/Encoder

Private Project - 2017

Encoder/Decoder for numbers into base62. These are string which consist only of A-Za-z0-9-_ and are compatible with any URL scheme while providing higher density than base 10 or base 16 numbers.


Lawrence Berkeley National Laboratory in Berkeley, California

The Distributed Energy Resources Customer Adoption Model (DER-CAM) is an economic and environmental model of customer DER adoption. My work focuses on improving and extending the graphical user interface and improving the stability and the quality of the software. The task also consists of planning, designing and developing a server/client infrastructure consisting of Python, .NET and Java with a REST Api for parallel optimizations.

Gut8 Text Editor

Gut8 Sachverständigenbüro, Freiburg, Germany - 2014-2015

Worked on an iOS application for real estate valuation.


MyFlexTennis, Freiburg, Germany - 2015

Web Application to find Tennis match partners. I developed this website as a freelancer.

Peak Flow Log

Private Project - 2014 (discontinued)

Peak Flow Log is an iOS App to keep track of different Peak Flow values for asthma patients over time. Individual graphical indicators help to determine the current health condition. The app is free and finances itself via in app advertisements. There exists also a so called “Plus-Mode” which removes the advertisements and provides an export function as well as more detailed statistics. This app is no longer available on the App Store.