Hi, I’m James Chen (Jianming Chen). I’m a freelancer (developer), consultant, and the founder of Centax, Inc., a consultancy building apps/solutions for partners and clients.

I write and contribute to open source software and make apps.


As a software developer, I started my career back in colleage. In early 2000’ I started building E-commerce and Travel websites with Microsoft’s Classic ASP1. That was the beginning of many ‘startup’s and adventrures I got myself involved along the way.

Since 2008 (after I played with Ruby a few years and learnt Ruby on Rails2 for one year) I’ve been working as a freelancer (fulltime and parttime, during the years to today).

Freelancing has always been my dream. The freedom to allocate time as I wish, to decide when and where to work, and to choose who to work for/with…


In 2015 I founded Centax based in Japan. While I still love programming and development I’m also eager to learn consulting, marketing, and all other things that interest me or would help my personal development and business.

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