Wolfgang Holzem

Expert Java Developer (20 Years+)





GitHub: https://github.com/ WolfgangHolzem/


Current location: Germany

Working remote


Profile Java & PHP Developer and Blockchain enthusiast that uses holistic thinking and attention to create sophisticated applications in the B2C, B2B and G2G network environment. 20+ years experience in the development of JAVA applications.

Server and Documents Management.

Branchen Erfahrung: Banken ( International und Local), (Bafin, FITS, Smaragd TCM, Swift, Sepa,PKI, Share Point), PSD2 ( 15 years+)

Airtransport and Logistic, Travel and Hotels, Industry Financial Services,


Experience Senior Software Developer - JAVA Jun 2014-Present (Remote Projects via SecureScrypt)

Head Developer for a Sentosa Group Singapore FinTech project with the integration of a payment gateway across 16 countries throughout Asia. Webhooks development for Wechat Pay, Alipay (Ant Financial), Bangkok Bank, Thai Military Bank, Siam Commercial Bank, Kasikorn Bank, CIMB Bank, Maybank, DBS Bank, ATM Bersama, BCA, BanNet, Bank BRI, BNI, NETS Singapore, HDBank, Mandiri Bank, Promptpay, UOB and VIB Bank. 7/11 and Tesco stores. PCI (Global) and PSD2 (EU wide) compliance knowledge including JAVA coding for the integration of AML and KYC projects. Blockchain integration

Eclipse JAVA EE


Co-Founder - eHalal Network Pte Ltd Singapore Jan 2018

Re-Development and customization of an OpenSource ERP (PHP 7.2) System forked from GitHub. Developing a SCM module layer on Top of the ERP system. Setting up a Big Data Mining system for the capture of all global Halal certificates worldwide, issued by 189 different Halal certifications agencies worldwide. Data is automatically verified and directly injected into the ERP system, auto generation of user-id's and passwords for the manufacturer for each Halal Certificate. Automatic Electronic Billing system including with optional functions to connect via an Electronic Data Interchange (EDI) system for billings and payment. Developing an E-Commerce Shop and testing Magento via Spryker (None VM).

PHP Script Development to export the Halal Certificate Number, Name of Product, Date of Expire and generate a fully automated Smart Contract on Blockchain with the creation of a Public and Private Key. PHP runs as a cron job and monitors the SQL server for new entries.


Head of SW Development - EuroAsia Communications P/L - Sep 2009

a)   Blockchain Software Development Projects under EuroAsia Communcations Pte Ltd

1)   Developed a private blockchain network based on node.js

Exchange transactions between different participant's using encrypted messages with the signature of each user. Transactions are stored as blocks in a distributed ledger.

2)   Developed in Solidity smart contracts for the Ethereum platform



3)   Tested and deployed Hyperledger code on a evm (Ethereum Virtual Machine)

4)   Coded in both Golang and Hyperledger for Ethereum on Tendermint

5)   Forked available blockchain source code from repositories.

6)   Agile Project Management/SCRUM


b)    Sony Ericsson - Developed application functions, features and unit testing for Sony Ericsson World Cup Mobile Application on all J2ME and Experia devices. Development in Eclipse JAVA IDE with Mylyn, Maven and Gradle integration. Backend development on Oracle Database 11g with JSON REST API

Localization in Bahasa Indonesia, Traditional Chinese and the Spanish language. (Project Length: 9 Months)

Project Website: https://www.sonymobile.com/


c)   Singapore Telecom (SingTel Group)

Mobile Application in JAVA for Singtel, Optus, Airtel and Telkomsel Developed in Eclipse JAVA IDE with Mylyn, Maven and Gradle integration.

Backend Development on two LAPP servers with PostgreSQL Database servers and integration with the JSON REST API.

Headed the localization team for Bahasa Indonesia, Simplified Chinese, Thai, Vietnamese, Malay,Hindi and the Bengali language.

Headed the A/B testing team for revenue improvement/CTR

(Project Length: 24 Months at multiply locations in Singapore, Indonesia and India. Project Language: English, Indonesian and Thai)

Project Website(s):

https://www.singtel.com/ www.airtel.com/ www.optus.com.au / www.telkomsel.com



d)    Bonnington Group Limited - Dubai, Dublin and Eastbourne

Corporate Mobile application for all Bonnington properties in the UK, the UAE and Ireland. Developed in Eclipse JAVA IDE with Mylyn, Maven and Gradle integration for the Android and J2ME devices and Xcode 4.2 for iOS devices.

Headed the UI Design team

(Project Length: 6 Months - Project Language: English) Project Website: http://www.bonningtontower.com/


Project Manager BMAsia Limited (Hong Kong & Thailand) - Sep 2016 - Mar 2017 Setup the OpenSource Streaming Platform (Icecast).

Linux System Setup (Centos 7) and Administrator.

Centovacast Integration (AAC)

Website and Shop Integration (Magento) (English/Thai and Chinese)

Development of a Payment Payment Gateway in PHP accepting payments by Visa, Mastercard, Amex, JCB, Online Banking Transfer with Bangkok Bank, Krungthai Bank, UOB



Bank, Siam Commercial Bank, Kasikorn Bank and Krungsri Bank. and over the counter payment with JustPay, Mpay, BigC and Tesco Lotus (OTC by Barcode and QR Code). Develop a Network Streaming Server under the Open Source Platform from the XMBC Foundation including the development of plugins in the Python programming language. (Project Length: 6 Months - Project Language: English and Thai)


Senior Software Development Pacific Asia Travel Association Sep 2013 - Aug 2014 Development of the backend and frontend of an in-house event Management system for the annual Pata Travel Mart. Developed in PHP with Eclipse as the Development Tool.

Backend Server was based on MySQL Database

Developed a Mix and Matchmaking application in Eclipse for JAVA EE (Spring Framework) for the computing and matching of 280 Buyers with 400 Sellers in 5,880 time-slots (10 minutes). Integration with an online and offline payment gateway (Visa, Mastercard, JCB and AMEX and Wire Transfer).

In charge of UI design/Web and Mobile Mockup. Training of the local IT team at PATA HQ.

Weekly meeting with the CFO to optimize the software development to stay on budget. Reporting directly to the CEO, CFO and Director of Event Marketing.

(Project Length: 12 Months - Project Language: English and Thai) Project Website: www.patatravelmart.com


Project Manager Asian Trails Group (Kuoni AG) Jul 2012 - Jul 2014

Developing both the front-end and back-end in Eclipse PHP for AT's B2C portal with an outsourcing team, based in the United States, Canada, Bangladesh, India and Pakistan. Developed 16 Android Applications in Eclipse for JAVA IDE with Mylyn, Maven and Gradle integration and several iOS application in xCode.

Developed a PHP application with the Json REST API to connect to AT's backend offices (Oracle) in Bangkok, Beijing, Bali, Kuala Lumpur and Ho Chi Minh City to retrieve realtime rates and availability for hotel rooms, excursions, tour packages including multi country tours and airport transfers and update the records with a PNR (Passenger Number).

E-Commerce Shop developed from Magento OpenSource Code (25%)

Using the Agile development technique of pair programming throughout the project. Developing a Payment Gateway that connects to AMEX and Krungsri Bank for Visa and Mastercard.

(Project Length: 24 Months - Project Language: English, Thai and German) Project Website: www.asiantrails.travel


VP Technical Integration AsiaRooms.com (TUI Travel Group) 1996 - 2006

Developing the Back-end and Front-end system in PHP (Line coding) and after 2002 in the Eclipse PHP IDE and Javascript. E-Commerce Shop developed inh-ouse.

Server and Network Maintenance (Sun Sparc Servers with mirrors at locations in London, Toronto and Singapore)



A/B Testing on different website functions (revenues and speed performances). Developing a Payment Gateway with Siam Commercial Bank to clear online payments for Visa, Mastercard and AMEX cards/

(Project Length: 10 Years - Project Language: English and Thai)

From 2006-2007 Technical Advisor to TUI Travel Group after the takeover. Project Website: www.asiaooms.com


Senior Software Consultant Info Highway Co., Ltd 1993 - 1996

Software Advisory to LTU Thailand, Diethelm Group, Bayer, Osram, Siemens, Dusit Kempinksi Group, Cable & Wireless Group, Bangkok Bank, Lamthong Bank, Samaggi Insurance, Thai Prasit Insurance, Lufthansa Thailand, etc.


Adviror Saigon Hi-Tech Park - 2001

Advisory to the stakeholders of the park to establish global industries

Education Grund und Hauptschule Suedlohn (1970-1980)

Skills Solidity (Eclipse YAKINDU), Ethereum, Eclipse for Java/Java EE & PHP, Golang, Hyperledger,

Tendermint, Corda, Apache Maven, Javascript, JSON, XML, Linux Administration (RedHat, SuSe, Centos, Fedora, Ubuntu)


Interest Travel, Open Source Software, Independent Music, Decentralized Software Applications, Cryptography


References On Request or via SecureScrypt Germany