Panos Matsinopoulos

Senior Software Engineer: Love Writing and Reading Software, Taking Entrepreneurial Risks, Teaching Computer Programming & Blogging here or in many other places. I also Love Music and I can call myself a small pianist!


I love software engineering. I am passionate about my job. I find it the most creative job that one could have.

After a long software engineering life that started with C/C++, then went to Java and then to .NET Visual Basic/C#, the last 12 years, I have been developing web applications using Ruby on Rails.

I believe that Ruby on Rails dramatically increased my web application development skills. REST, HTTP, testing and the whole family of tools around it tremendously improved the quality of code I deliver.

I am always willing to take new challenges on big projects. My biggest reward is not the money that I get, but the software that I create when it makes their users happy to use it.

"Test is my friend" and "Customer has always something useful to say when making a comment about my software." It is my task to turn it into something valuable that will render my final work even better. "The enemy of good is the better one."

Nevertheless, I never go without planning and I like working on specific non-moving targets. Focus, Focus and Focus.

Currently, I am wired up with the [Shape Up Process](, and I have recently become an
[ Author too](


  • Ruby
  • Ruby on Rails
  • React
  • React Native
  • PostgreSQL
  • MySQL
  • JavaScript
  • TypeScript
  • Bootstrap
  • jQuery
  • HTTP
  • Neo4J
  • Riak
  • Solr
  • TDD
  • BDD
  • Cucumber
  • Capybara
  • Selenium
  • HAML
  • Continues Integration
  • TeamCity
  • Jenkins
  • Factory Girl
  • Twitter Bootstrap
  • Amazon Web Services
  • Facebook API
  • Twitter API

And finally the traditional CV:

What do I do for a living?

I am a Software Engineer specializing in Web Development.

When might I be useful to you?

If you need to deliver with Ruby on Rails, then I can be useful to you. I know quite a lot of stuff from Ruby on Rails and I can design, implement and test end to end.

Here are my CV details (only the most important ones):

Work History

My Projects

Read about my Ruby on Rails Projects here: Projects


November 2010 till Today:

E-Travel S.A. & Fraudpointer S.A. as Senior Software Engineer


Ruby, Ruby on Rails, MySQL, Solr and various other tools for Web Application Development. Team Leader with many different approaches on project management to keep my team happy and productive.

December 2007 till Today:

Rayo ( as Senior Software Engineer

I took the responsibility to design and develop a series of Applications:

  • RNPB – Rayo Number Portability Broker. A JBoss hosted Application with an Oracle Database backend that has the responsibility to accept requests from NRDBP (National Reference Database for Portability - ΕΒΔΑΦ) and carry out the necessary internal tasks to fulfill them.
  • Rayo SMS. A .ΝΕΤ IIS hosted Application with an SQL Server backend. Data management of contacts and a Windows Service to send SMS over an SMS gateway.
  • Mylos Art Café ( A .NET IIS hosted Application with an SQL Server backend. This is a presentation web site.
  • Rayo Payments Management System (PMS). Α JBoss hosted Application with an Oracle Database backend. I had the responsibility to design the database schema. This is an Application that has the responsibility to import files from external payment channels, and, after processing, with manual and automatic ways, to push results to Billing and ERP systems.

e-rhetor ( - Senior Software Engineer

  • FaxRhetor. This is a .NET IIS hosted Application with an SQL Server backend. Data management application with enhanced features for Fax Page and Document Management. Also linked to CRM/Siebel.
  • WebRhetor online TtS Service. This is a .NET IIS Web Service with an SQL Server backend database.

Jun 2006 - November 2007:

On Telecoms S.A. - IT Department - Technical Project Manager

  • IT Applications Project & Technical Management (CRM, Billing, Mediation, Company Web Site, Web Self Care e.t.c.). I had 24 people in my team and I had to design and implement a lot of IT projects, both internally and with third-party products.

July 2004 - June 2006

Intracom S.A. / OSS/BSS – VASS/PrePaid Billing Solutions - Technical Project Management

  • Implementation of Prepaid Billing Solutions – LogicaCMG – at COSMOTE Group GSM Operators
  • Prepaid included modules such as the following:

    • (a) Customer Care System (running on HP-UX 11i with Informix Database Server – cluster configuration)

    • (b) Prepaid Billing for Voice (running on HP-UX 11i, with Informix Database Server – cluster configuration)

    • © Prepaid Billing for other Data Services (SMS, MMS, Content, e.t.c) (running on HP-UX 11i, with Informix Database Server – cluster configuration)

    • (d) Data Warehouse Application (running on Windows 2003 Server, with SQL 2000/5 Database Server)

    • (e) Telecom Switches (EXCEL/Lucent) which communicated real-time with the MSCs using either ISUP or INAP protocol. They had redundant equipment (two CPUs, two SS7 cards, two E1 cards, two IVR Announcement Cards, e.t.c.)

  • Capacity planning. I took part in the process of agreeing with the customer which is the correct h/w and s/w configuration for their site taking into consideration their requirements (number of subscribers, call profile, usage of the network, e.t.c.

  • Design of Specific Activities on the Field – Method of Procedures. I had the role to design several technical activities at customer site. Activities included, among the others,

    • (a) installation of new version of operating system

    • (b) installation of new version of the database server

    • © installation of new releases of application software

    • (d) installation of new h/w, such as UNIX application servers, ISUP and INAP telecom switches, external hard disk subsystems like EVAs, MSAs e.t.c.

    • (e) performance audit of Application and Database servers.

    • (g) monitoring of telecom switches.

    All these technical activities that I dealt with, involved a high risk of failure, since they had to do with the Prepaid Platform, which was a Real-Time billing system. We had to design the procedures in such a way in order to avoid outage of service, or at least, minimize it as much as possible.

  • Resolution of Support Issues. I had to follow up on all open tickets of the customer assigned to me. I had to lead the engineer responsible to solve the problem and I had to speak with the vendor in order to speed up the technical resolution

  • I also had to maintain and enhance Intracom specific applications. Mediation and Recharge of Prepaid Accounts over ATM (bank Automatic Teller Machines)

September 1998 - June 2004

Intracom S.A./ OSS/BSS – Business Support Systems - Software Engineer

  • Usage Data Collection and Conversion System (Billing Mediation Device). OTE, OTESAT, VODAFONE, GLOBUL

    • For OTE: I was in the team that evaluated and installed the Mediation Device of OTE that would consolidate all the CDRs generated on all PSTN/ISDN switches (240, Ericsson and Siemens) deployed all over Greece. The product that I dealt with was the FCC (France Telecom – Sofrecom product). Application is still under operation.

    • For OTESAT: I designed and implemented the OTESAT Mediation Device. Application had to consolidate 5 different sources of CDRs and provide RATING module with a unique format. The final Application was pure Object Oriented and implemented in C++. It included all necessary Mediation modules, like, collection, validation, duplicate checking, unification, storage into a database, e.t.c. Application is still under operation.

    • For VODAFONE: I was in the team the evaluated and installed the Medation Device at VODAFONE Greece. It was a COMPTEL (Finish company) product. Application is still under operation.

    • For GLOBUL: We deployed at GLOBUL (largest GSM Operator at Sofia/Bulgaria) the same Mediation Device that I have designed and implemented for OTESAT. Application is still under operation.

  • Billing and Customer Care System


    • For OTE: I have designed and implemented the RATING module of the Billing system of OTE. This was completely Object Oriented designed and C++ implemented. Fully multi-process and multi-threaded, running on HP-UX operating system. At the back-end there was an Oracle Database. Application was capable to rate around 30 million CDR’s per day with a complex of more than 300 Products with different Tariffs. Also, system was designed to provide with interconnect billing and all alternate fixed telephony providers were getting reports about their subscribers’ usage. RATING engine was also designed to import into the Billing system records that were rated by other, external, systems. System is still under operation.

    • For OTESAT: We have deployed the same RATING module that we have deployed at OTE. However, the RATING had increased complexity in order to deal with INMARSAT clearing too. Hence, each record needed to be rated both for the end-customer and for the INMARSAT authority in order that OTESAT to pay to them their share about channel usage. System is still under operation.

    • For GLOBUL: We have deployed the same RATING module that we have deployed at OTE and OTESAT. However, it was extended to support GSM products (all basic and supplementary services, both voice and data). Also, we have implemented modules to export and import TAP ½/3 records (for the roaming subscribers).

    • For COSMOROM: Same like in GLOBUL..

  • Service Provisioning System

    • TELESTET, product: Object Switch Service

    • Provisioning (KABIRA)

    • For TELESTET: I was part of the team that was trained to use the Object Switch (KABIRA) and implemented the project of Service Provisioning at TELESTET. System was interfacing LHS Billing System on one side and SOG (Ericsson provisioning mediation) on the other.

  • Network Service Order Processing


    • (Romania)

    • For all these customers: I was the chief architect of an application that was used for Provisioning. The system was fully Object Oriented and it was implemented in C++ by a team that I was leader of. The operating system was HP-UX.

  • State Transition Management Toolkit

    • (Management of the Life-Cycle of Business Objects)

    • Intracom Internal Product: A software module that was included inside the Product and Order Management Applications. It was part of a family of software modules that were used to turn Product and Order Management Applications into two fully configurable Business Applications. It was used to speed up the creation of Products and the management of Orders. Software module was fully Object-Oriented and implemented in java with Enterprise Java Beans and Borland Application Server.

  • Business Development Environment Toolkit

    • (a CASE Tool for Business Object Modelling and Physical Data Modelling)

    • Intracom Internal Product: Like the State Transition Management Tool, this software module it was internally developed in order to help our engineers design and implement other products, like Product and Order Management. It dealt with two layers of the application design, the Application layer and the Database Layer. It was fully Object-Oriented and implemented in java with Enterprise Java Beans and Borland Application Server.

  • Product Catalogue Management

    • Intracom Product: An Enterprise Java Beans application used to define the Products of an organization (Service Provider, Telecom Operator, e.t.c.). I was part of the design team and leader of the implementation team.
  • Order Management System

    • GLOBUL

    • For GLOBUL: I was chief architect of the Order Management System that is now deployed at GLOBUL (GSM Operator in Sofia/Bulgaria). I was also leading the implementation team. Application was implemented with Java Enterprise Beans.

January 1997 - August 1997

  • University of Athens, Dep. of Informatics/ Project Assistant

    • Development and Support of Internet applications developed in University of Athens, Dep. of Informatics, in the context of GLOBE (Global Learning and Observations to Benefit the Environment,, In parallel, I was involved in the project “Physical Environment and Nature in Ancient Greece”, as HTML/WEB Designer.

Professional Training

July 2005

  • Hellenic American Union - Business Management Consultants
    • Preparation Course for the Project Management Institute Certification

April 2005

  • Hellenic American Union - Business Management Consultants
    • The Art of Project Management

September 8th, 2004

  • Intracom - Cost and Budgeting

July 2004

  • Intracom - Basic Project Management

15/3/1999 – 24/3/1999

  • HP - HP-UX Internals

25/1/1999 – 29/1/1999

  • HP - HP-UX System Administration


  • IEE - Shaping Tomorrow’s Networks

5/2/1998 - 6/2/1998

  • IEE - Mobile and Personal Communications in the 21st Century

General Education

September 1998

MSc in Telecommunications (1 year) from University College London - Distinction

December 1996

Graduate Degree in Computer Science and Telecommunications (4 years) from University of Athens - 8.07 (Very Good)

Awards - Honours

August 8, 2005 - January 31st 2009 - Project Management Professional

Foreign Languages

English - Both Oral and Written Very Well Spanish - Basic