Mission Critical Engineer @ Analytics in scale, Hadoop ecosystem, Spark, machine learning From July 2015 to Present (6 months) Amsterdam Area, NetherlandsMember of the Board of Directors @ From January 2015 to Present (1 year) Software Engineer - Backend @ From September 2014 to June 2015 (10 months) Amsterdam Area, NetherlandsSoftware Engineer - Master Data Management @ Designing and implementing high availability systems, mainly using: • Python • MongoDB • Celery • Redis Designing and implementing backend services for a number of company products and solutions. From October 2013 to August 2014 (11 months) Senior Web Developer @ Building a Data Warehouse: • Analysis of data sources • Analysis of requirements • Architecture design and implementation of periodic and near-real-time extraction from: ◦ MySQL, MongoDB, XML, JSON, CSV Analysis, troubleshooting and optimisation of MySQL and MongoDB. Assistance of development team in the optimised use of the ORM. Web development in PHP with TDD. Using git, phpunit, Jenkins, agile development and pair programming Python for service prototyping and data extraction/manipulation/reporting fron MongoDB and MySQL/MariaDB From October 2012 to October 2013 (1 year 1 month) Software Developer - Analyst @ Software development with Object Oriented Principles through the stages of requirements, analysis, implementation, prototyping, testing and maintenance. Analysis of real-life data structures, implementation of complete software solutions (e.g. banking transactions, Greece Unified Phone Registry). Supporting and enhancing legacy systems with new functionality. Ad-hoc reporting tools for existing databases and software systems. From August 2008 to December 2011 (3 years 5 months) Datawarehouse - Operations Specialist @ Extensive implementation of new reporting tools and procedures. Maintenance of existing reporting structures and tools. Daily maintenance, running, and expansion of a large-scale database, highly critical in its mission of delivering daily, weekly and monthly reports for the Customer Support, Sales, Revenues, Interconnection and other company departments. Implementation of fraud detection procedures. Overview and fault-detection of other IT systems: • SAP (accounting) • SIEBEL (customer support and customer orders) • IAS (billing) • Network traffic • Network port reservation system From March 2007 to August 2008 (1 year 6 months) Software Engineer - Research & Development @ Design, prototyping, development and testing of various applications in Java and .NET/ASP.NET, creating new tools for testing and debugging ISO 8583 messages. Security-centred smart card and digital certificates usage. Ad-hoc prototyping of applications for various R&D needs. From June 2002 to September 2003 (1 year 4 months) Software Engineer - Intern @ Design, prototyping, development and testing a communication server application in Java, facilitating the stateful communication of POS and ATM transactions to a bank’s system, based on ISO 8583. From June 2001 to September 2001 (4 months) IT - Internship @ System maintenance in the micro-computers division, development of small office applications based on the Microsoft Office suite. From June 2000 to September 2000 (4 months) IT - Internship @ High-level network administration, automatic generation of CISCO router scripts and settings. From June 1999 to September 1999 (4 months)

Master of Business Administration (M.B.A.) @ Strathclyde Business School From 2014 to 2016 Master's Degree, Distributed Systems Engineering @ University of Lancaster From 2003 to 2005 Bachelor's Degree, Software Engineering @ UMIST From 1999 to 2002 Foundation Year, Software Engineering @ UMIST From 1998 to 1999 Ioannis Charitopoulos is skilled in: Python, MySQL, Git, Linux, PHP, Software Development, Web Applications, MongoDB, Web Development, Software Engineering, Open Source Software, R, Data Analysis, Apache Spark, Java