During covid 2020 - 2023: SaaS services development for Virtual Event site. • Development attendee footprint tracking report system for Virtual event. Firebase (funnction, Hosting rtDB), AWS (Firehose,Athena,S3) • Feature implemented for eSaaS website. ReactJS, nodeJS, docker, AWS(VPC,ECS,RDS,S3,Cloudfront) • Dev customization feature by different Cilent, dev such as HKTDC SSO integrated, GTM, JWT, MongoDB, improved china user speed. ref: https://portal.eventx.io/ https://spot.eventx.io/ Before the covid 2017 - 2020: Build up team in Taipei. Lead a Event App/Lead retrieval App for Exhibitors n Attendee during event. Included Restful API Server using RoR (Ruby on Rails), Native iOS and Android, web services by RoR, Redis, Postgres in Linux. and Event web app implemented using Python. • As Technical Leader, team/resource management, design architecture, ensure the implementation follow the design, define the protocol, optimizing performance and security. • Development for most of Event iOS App core data & OCR feature in Native App, and solved complex problems. • Development for API Server using RoR, base on HTTPS implement RESTful & GraphQL api, Also did Contact data sync with Server • Design and implemented Contact data sync (include poor network handling) with Server (similar to google contact sync), to make sure the keep latest data on different device. • Investigate & fixed critical issue such as an lib issue we using in Checkin App(react native): DB support FullText search but had bug on sql parser(https://github.com/Nozbe/WatermelonDB/pull/664) ref link:
 Event n Lead retrieval app iOS: https://apps.apple.com/us/app/eventx/id1321224680?ls=1
 Event n Lead retrieval app Android:
 https://play.google.com/store/apps/details?id=com.eventxtra.eventx Checkin App iOS: https://apps.apple.com/us/app/eventx-check-in-classic/id1480321190 Checkin App Android: https://play.google.com/store/apps/details?id=io.eventx.esaas.checkin&hl=en_US

Working on an VoIP(Video/Audio) Service development. Included core lib of VoIP, Native iOS App, STUN/TURN and RTMP Server implements. Development the cross platform lib for VoIP, base on rfc 5245, 3489, 5389, 5766, develop protocol and solved complex problems. Development & Deployment STUN/TURN and broadcast Server, for VoIP and Live feature. • Improved audio/video codec performance issue. • Improved connection issue of VoIP between difference NAT. • Improved performance of the VoIP connection speed from 10secs to 3secs. ref link: https://apptopia.com/publishers/itunes_connect/984314326

Lead a B2B private cloud(behind firewall) IM services. included Socket Server using Erlang&Mnesia, Native iOS and Android, web services by PHP, Redis, MySql in Linux. • As Technical Leader, choose technical direction, design over all architecture, ensure the implementation follow the design, define the protocol, optimizing performance and security. • Development for part of IM iOS App core data & implements protocol base on TCP/IP socket, and solved complex problems. • Development for Socket Server using Erlang, base on TCP/IP implement XMPP(RFC3920) protocol(SASL rfc2222, TLS rfc5246 included), using both of Mnesia and mysql DB. Implemented high available and scalable multi-node(DB replication included). Improved performance 600k concurrent message and 5k message process per-second in 8core 32GB server. Design and implemented new protocol for message read status, message acknowledge & persistent group chat (both of public and private group).

Take over & Lead B2B private cloud bookshelf services. including editor in Windows PC application by C#, iOS by OC, Android by Java, web services by PHP,Mysql in Linux (LAMP) • As Technical Leader, choose technical direction, design architecture, define the data model and ensure the implementation follow the design. • Develop mobile side for improved performance in 3 months using native Objective-C & Java development iOS & Android replace the original with (JavaScript lib) Titanium. • For keep the PHP source code when deploy to customer, base php 5.3 develop ext lib (using C) for encoder the source code and runtime decoder. • For the editor(PC Application, build the ebook content) more competitiveness. Develop iTunes cracked application connection(send file, install, etc..) iOS device(Similar iTools but command line exe), let the editor can preview the ebook content in iOS device without jailbreak. Develop PHP web service of internal automatically compile (iOS, Android and PC application) sync with Git, define a rule let marketing guy can change the app name, icon, URL, resources and get the latest stable version to demo or deliver. ref link: https://apkpure.com/ourapp-reader/tw.com.ourdigi.ourapp.reader

Positions held included, senior engineer and Project manager. • as a Project Manager & Senior Engineer, Lead 5 project at same period for preload the application in Nokia N9 smart phone. Manage global resources also Technical consultant for QT C++/QML. 1. Lead Sina Weibo Application in N9 , remotely work with development team in Dalian(China), (Link below is the Nokia visit developer for QT/QML, the Allen Chan is me). http://www.meegoexperts.com/2011/06/sina-weibo-social-network-media-app-designed-nokia-n9-powered-qt/ 2. Lead Kaixin(just like Facebook in China) application in N9, remotely work with development team in Riga(Latvia). 3. Lead Trends & Hippo Reading(Ebook) application in N9, remotely work with development team in Dalian(China). 4. Lead ESPN application in Nokia Windows Phone 7(C#), and WP7 Example code for Integrate social network(Sina Weibo, Renren, Jiepang) in China. • Architecture and development OMA DM(Android JNI C) SyncML protocol for China Mobile. Lead and Technical consultant PIM Server(Oracle with J2ee in Linux) for China Telecom.

Positions held included engineer, senior engineer and Team leader. • Development web service of cell phone themes DIY (http://www.imolife.com), focus on backend make the each mobile platform theme pack development, set up environment and maintain(Using J2EE+MSSQL). • Construction and server application development news rss reader(J2EE & html reptile program) for China MII.(non-simple rss, but to parser the html content in the Rss Link). • Bluetooth camera Symbian application porting from Sony Ericsson UIQ to Nokia S60(Symbian C++). • Maintenance DCD(Data Carrier Detect) application in SonyEricsson UIQ(Symbian C++). • Development porting the China mobile IM application Fetion 2.0 from Nokia S60 to SE UIQ(Symbian C++). • Core development Translation Tools is called J2C(Java to C) lets developer coding in J2me generated 3 smart phone platform source code and install packet (J2me, C, WMC++, Symbian C++). Use Cases for China Mobile Fetion 3.0. Especially focus on string encoding(ANSI,UTF-8,UTF-16), and multi-threaded non-blocking queue. 5. Development Nokia pad N800(Meamo C++) screen monitor and remote system management application, and Nokia Symbian be monitored client application(Linux GUN C++). 6. Development DCD(Data Carrier Detect) application in HTC windows mobile 5.0 (WM C++). 7. Development SCREEN3(home screen news banner) Motorola WM client in Australia(Windows Mobile C++). 8. Development and design architecture DCD2.0 Application for Samsung SHP(NXP feature phone) platform, redesign architecture using C to develop core lib and onsite Samsung SHP development team to do the technical support. 9. Development and part of architecture design Willcom(4th Telecom in Japan) UIScreen, base on Windows Mobile 6.5 and QT C++ to do whole system UI screen and addition UI animation development(Qt C++, WM C++). 10. Development and Architecture design the lightweight JavaScript runtime engine in J2me, (research from Google V8, WebKit JavaScriptCore and SpiderMonkey).

• Development web Community property management system background business logic development, maintenance (J2EE+MSSQL). • Development MyBlog web services background business logic and DB model design, maintenance (ASP+MSSQL). • Maintenance Beijing Maternity Hospital Information management system, base on power builder 5.0 and Oracle 9.0 integrate with print hardware interface and bug fixed. • Development LAN management teaching system, function as desktop sharing, screen monitor and remote control. base on SNMP protocol and uTP using C#, participate and learn system architecture design.