Your hotkey to alternative software development

Past clients

Some of the clients i've done projects for:


Erik Hooijmeijer Ing. Erik J. Hooijmeijer (1971)

I have been building technical, administrative and entertainment software professionally since my college days. Anything from small to medium size projects often doing the design and part of the implementation. I look ahead, solving problems before they occur. Besides software design and implementation I like to communicate and have been a trainer for several years on a part time basis. Computer Security is another interest I've been pursuing, anything from an application security assessment to penetration tests.


  • Senior Developer
  • Ethical Hacker
  • Coach
  • Team Lead
  • Scrum Master
  • Trainer

Branch Expertese

  • Software Industry
  • Aviation
  • Metrology
  • Meteorology
  • Logistics
  • Intellectual Property
  • Education
  • Automotive
  • Identity Management and Biometrics
  • Commodity Trading

Programming Languages

Language Period Grade
Java 1996-Now Excellent
Delphi 1995-2005 Good
C 1995-Now Good
SQL 1997-Now Good
HTML/CSS 1997-Now Good
JavaScript 1997-Now Good
Pascal 1993-1998 Good
680x0 Assembly 1991-1997 Good
TMS370 Assembly 1995-1997 Good
6510 Assembly 1987-2020 Good

Development Environments

Product Period Grade
Eclipse 2001-Now Excellent
IntelliJ 2015-Now Good
Netbeans 2005-Now Good
Websphere Studio Application Developer 2001-2007 Good
Delphi 1993-2005 Good


Description Score Year
Pentester Lab 2019-...
Certified Ethical Hacker (C|EH) 2013
Certified Secure - All Certificates 2012
Sun Certified Java Programmer 1.2 93% 2002

Responsible Disclosures

Site / Product Version Description Reported Resolved
Ebase Xi/Verj.io 4.5.2+ Remote Code Execution Okt 2018 Nov 2018
haarlem.nl Misconfiguration Aug 2018 Aug 2018
iffr.com Information Disclosure Jan 2016 Jan 2016
groningen.nl Misconfiguration Okt 2015 Okt 2015
ad.nl Open directory Okt 2015 Okt 2015
Ebase Xi 4.5.2 XXE Dec 2014 Mar 2015

Specific Knowledge

Description Period Grade
J2SE 1996-Now Excellent
J2EE 2002-Now Good
Spring/Hibernate 2006-Now Excellent
Android Platform 2010-2019 Good
Wicket 2005-2017 Good
Webservices 2003-Now Excellent
Computer Graphics 1995-Now Good

Methods and Techniques

Description Period Grade
Scrum / Agile 2009-Now Excellent
Object Orientation 1997-Now Excellent
Component Based Development 1998-Now Excellent
GoF/ Software Patterns 1998-Now Excellent

Training and Education

Institute Description
TSTC CEH Fasttrack
jWorks Domain Driven Design
Savonije B.V Consultancy Skills 2
Savonije B.V Consultancy Skills 1
Cap Gemini Project Leader 1
ICGroup B.V. Object Oriented Analysis
ICGroup B.V. Object Oriented Modelling with Patterns
HR&O Polytechnic Faculty Electronics - Information Technology