electronic brain surgery since 2001



  • concepts
  • mockups
  • estimates and offers
  • community management



Web Frontend

  • HTML
  • CSS
  • LESS
  • Accessibility
  • JavaScript
    • vanilla
    • jQuery
    • prototype
    • React
    • Angular
  • gulp


  • oAuth
  • SSO Kerberos NTLM

Desktop Frontend

  • C#
  • Delphi
  • Java

API Integration

  • Paypal
  • Google
  • Mailchimp

Backend Programming

  • PHP
  • Perl
  • Python
  • nodejs


  • MySQL
  • SQlite
  • Oracle
  • Postgres
  • DB2

System Administration

  • Apache
  • FPM
  • Monitoring
  • Postfix, QMail, Exim
  • Dovecot
  • Firewall
  • VPN

System Programming

  • PAM
  • Krone C

Network Protocols

  • lots of knowledge on HTTP and related RFCs. wrote my own HTTP 1.1 compatible client library for DokuWiki. able to manually speak simple HTTP via telnet.
  • lots of knowledge about SMTP and related RFCs. contributed to the txthinking/Mailer library. can speak simple SMTP via telnet
  • lots of knowledge on mail encoding. wrote my own classes to construct multipart mime mails and correctly encode UTF-8 mails
  • basic knowledge on POP3 and IMAP. used to be able to speak POP3 via telnet when it was still popular
  • SNMP
  • LDAP ActiveDirectory
  • wrote my diploma thesis on ad-hoc routing protocols

Operating Systems

  • use and can manage Windows but it's not my favorite system
  • started learning about and administrating Linux systems during civil service in 1999
  • worked as system administrator for CosmoCode for several years
  • fluent with Debian and Arch Linux, but worked on Redhat, SuSe, HP-UX and other unix-like systems
  • able to indentify and debug common problems on Linux including init and systemd, udev, xorg and other core systems


  • build my own PCs since after I got my first own computer (a 386 somewhen in the early 90ies)
  • can set up general network equipment and make network cables (started with 10baseT but know how to crimp modern CAT cables and fit patchpanels)
  • built a 3D printer from a kit
  • there's a yet unfinished Raspberry Pi project where I use GPIO to talk to sensors
  • can solder but have not much knowledge in electronics eg. I can built circuits others designed but can design my own.