Johan Hedin Email & Phone Number

Stockholm, Sweden

Stockholm, Sweden

I work with the CSAM XDS, Infobroker and Medimaker products. The most resent products are built on Scala, Akka, Cassandra and non blocking I/O with back pressure.

Stockholm, Sweden

During an internal reorganization, the work title did change. The daily work was however not affected. During this period, the automatic testing of the X7 products was greatly improved. I built a test system on VMWare ESXi and then Citrix XenServer with an iSCSI storage on OpenSolaris on a limited budget. The system is used for the automatic integration tests that test the full suite of products by interacting with the APIs.In the products, I introduced Scala as a language for new modules. The new GUI are written as HTML/JavaScript applications with REST/JSON APIs to the server. Also, the work loads forced us to start using Akka Actors, ElasticSearch and patterns like event sourcing. We have also fixed several JBoss resource leaks. The products are in progress of transfer from JBoss to Glassfish.I have during this period also been working on the design of the regional and interregional clinical access to radiology information in region Sjælland in Denmark. The solution involves most of the X7 products. The solution is deployed in two data centers with synchronous replications of the transactions between the centers and an 8 node ElasticSearch cluster located in both of the data centers.

eCare AB was acquired in 2007 by the Finish company Mawell. Focus has been on Infobroker and XDS architecture. During the period, the technology, and also the work loads have advanced. The products on Solaris are transferred to Linux. Further, the products have matured with, e.g. SNMP monitoring support, administration GUIs and greatly improved packaging.Two more Swedish companies, Brainpool and Euromed, was acquired by Mawell during the period. I was involved in the process in both of the acquisitions.

Senior system architect at eCare AB and later CTO. I have during this time been the head system architect of the award winning Feedback system and the Infobroker system. Both systems are built in a JEE framework. Infobroker is fully clustered system without a single point of failure. XA-transactions with transaction recovery are used internally in order ensure data integrity. The business logic is largely handled through an BPM engine. During the years, eCare has grown from a small entrepreneur company to a medium size software company. As one of the first employees, I have been involved in all parts of the company from sells to support and also in the found raising for the company.

The Ph.D. thesis work contained modeling and computation of RF heating in toroidal fusion devices. The work was done in an international collaboration and competition. I was twice appointed as one of the Swedish delegates at the prestigious IAEA fusion conference.In the publications included in the thesis, the first self contained calculations of RF heating was presented. The calculations was done in parallel on a cluster of Sun workstations. Since the workstations was not exclusively used for calculations, and also, had different capacity, a system with dynamic load balancing was developed. During 20% of my employment at KTH, I was the system manager of our Sun system.

Ph.D., Fusion Plasma Physics

Activities and Societies: Ph.D. student representative at the faculty board.

M.Sc., Enginering Physics

Activities and Societies: Force, Fysikalen