Curriculum vitae

As part of the development team at this Payment Service Provider I take care implementing new payment methods or changing existing ones.

Implemented functional changes to a rather complex and near realtime feed of traffic data.

The grammar, morphology and phonology of the Dutch language will be made availlable on the web. I advised on ways to convert current scientific papers and books and on ways to maintain the converted material. I gave further advice on how to setup the new LanguagePortal site so that all embedded knowledge about the language can be accessed.

Vigilance is a small company that operates in the security market. For them I wrote software to write reports on reconnaissance images conforming to NATO standards, software to manipulate MPEG transport streams to combine video and meta data and I did a small embedded project on an AVR32. Apart from software I did quite some hardware integration and some analog electronics (a pre-amplifier for the A/D converter on the AVR32).

Responsible for the design and development of a backend system and a Content Management system for a Flash site. Communication with Flash was done through OpenAMF.

Co-developed a corporate (DHTML)web site for Achmea. My responsibility was the non-js version and all backend communication (through AJAX) with the frontend.

The dutch railway is working on a new passenger information system. All railway stations will be fitted with overhead monitors (TFT/LED displays). I was responsible for the Linux distribution for the embedded computer of the TFT displays.

Displays like these come with numerous sensors that must be read and monitored. I wrote software to run on the embedded computer that interacts with the sensors-controller and a central management server.

The displays are networked over GPRS which took extensive fine- tuning. I Implemented IPSEC with X509 certificates to meet security demands and created a setup with a minimal C(ertificate) A(uthority) using openssl and Linux shell-scripts.

The new website of Transavia aims to integrate ticket sales and sales of third party products in such a way that customers never notice the distinction between Transavia and the third parties (think of hotels, rental cars and packaged holidays).

The differences are hidden by communicating online (some variety of XML over HTTP) with a third party and displaying the results as an integral part of the site.

As a base for this application Shores was chosen, an opensource framework developed by me. It uses XSLT as a formatting language.

My personal part was the communication with a Navitaire flightreservation system (NewSkies). This core system is queried and updated over a SOAP interface. All flight bookings on the site go through this SOAP channel.

This customer is in the process of moving from Progress to open source. I started with building a proof of concept with Swing on the client and Spring and Hibernate on the server. The two are joined with Hessian over https. The Swing client is made available through Webstart.

For the proof of concept I built a reusable framework that uses metadata for dynamically building components like tables with searchfields in the header. The framework uses JGoodies for laying out forms. Rather than using a gui-builder the forms are build in code, using JGoodies this is a breeze. The framework has all the usual bells and whistles using reflection to minimize work and interception (dynamic proxies) for uniform error handling.

Together with a junior programmer I built a large application based on this work for a health care organization. The framework is extended with security. The standard Acegi framework did not work well with Hessian and rich clients. The security framework allows for constraints like "if owner of document or supervisor and current date less than creation date + 3 -> allow update".

At this customer I extended the SOAP interface to a large human resource application. All SOAP messages where in HR-XML and the framework we used was Axis. Furthermore I did some reports with XSLT and FOP.

For this contract I redid the way registration forms were generated. Due to the nature of the existing codebase standard xml data-binding was not a good choice, so I made a custom data-binding with jdom, mapping tables and introspection. This way the xml needed for the forms could be generated easily and either transformed into html or PDF using xslt. For the PDF generation apache Fop is used. Generation is done on-the-fly.

The second and smaller part was a re-write of the ldap code, which I ported and cleaned up from using the Netscape sdk to the standard JDK way.

Wrote a requirements document for a monitoring tool.

Wrote a conversion script for a massive ldap update. Based on an export of a crm system and the current content of the ldap server I created an ldiff for an up-to-date ldap server. The repository contained several million records.

The contract started as a very short contract to write some XSLT stylesheets, but it turned into a real E-Commerce job. I reworked the checkout and shopping cart part of the application in a similar fashion as I did for Verkade based on a dispatcher servlet and XSLT.

For a non-profit organization that will remain anonymous we have built a CRM application to keep track of their contributors. One of the design criteria was database-based optimistic locking. As there seem to be no CMP implementations that have that I skipped the entity beans all together and build a code generator to generate the code to access a table (with optimistic locking and logical delete) The calls to these generated objects are wrapped in a DAO and are called from the session beans. Transaction management was left to the container.

The client was build in swing which I discovered performs very well if you know what you are doing. Most of my work was helping design the application and building the back-end, that is all the ejb stuff. For the client-side I build the RMI based communication and a 'code table' editor in Swing. The editor generates the search and edit screens based on xml metadata.

Together with one other architect/programmer I worked with KPMG to hammer out all of the business processes that had to be mirrored in the software and I worked with the financial and marketing people to lay out the database such that all their information needs would be satisfied.

Apart from the software side I helped design and setup the hardware infrastructure. We opted for a fiber-coupled central storage that all nodes can reach. Instead of the conventional cluster each node is expendable, all nodes know how to take over the other nodes function. To make replacing easy we used kickstart (like jumpstart) to install a new system. So within 10 minutes a system can be replaced.

Note: Digipay got into financial trouble, they never went live. The company has been resurrected and I am told they target different markets now.

This framework is the basis of Shores

Refined and extended the XML to database framework built earlier. Improved the manageability of the framework and added the possibility to run script driven functional tests.

Beside the development, I looked into and solved performance and network problems in the application server and the ldap server.