Reviews from current and past clients...

"Daniel McQuillen has provided software development services to Lawrence Berkeley National Laboratory (Berkeley Lab) for the U.S. Department of Energy's award-winning BETTER software toolkit since 2021. He is an asset to the BETTER team and highly skilled in his ability to grasp client needs, recommend solutions, and execute solutions with quality and efficiency. I've been particularly impressed with his work to introduce more dynamic approaches to portions of the user interface, support multilingual functionality, and implement technical enhancements to the application programming interface (API). Daniel is a superb software developer and a pleasure to work with!"

Carolyn Szum
Investment Team Co-manager - Net Zero World Initiative
Energy and Environmental Policy Researcher | Whole Building Systems Department
Technologies and Urban Systems Division | Energy Technologies Area
Lawrence Berkeley National Laboratory

"iBiology has had the great privilege of working with McQuillen Interactive for over seven years. Daniel built and continues to adapt/improve our online courses platform ( In addition to delivering this key product, Daniel also designed and implemented both an analytics dashboard that we use to track course performance as well as an automated email system that allows us to communicate and engage with our course participants. All of Daniel’s work is beautifully-designed, high performing, and really easy to use. But he doesn’t just deliver outstanding products, he’s also fantastic to work with. Daniel brings so much more to his projects than you’d expect from a programmer. As a small nonprofit organization, Daniel has been extremely adept at helping us achieve our ambitious goals and milestones with limited budget. And he does so with great professionalism and efficiency. He is hardworking, reliable, and motivated; he takes initiative and is adaptable to our constantly evolving needs and demands. Furthermore, he is extremely communicative and responsive, and just an overall excellent communicator (which is really important to the staff who are less tech savvy). We can’t say enough good things about Daniel. He has all of the great qualities you’re looking for in a programming consultant."

Shannon Behrman and Alexandra Schnoes
Program Directors
iBiology Courses
Science Communication Lab

“Daniel has worked with Lawrence Berkeley National Laboratory since 2008 on our COMFEN Building Façade Design Tool. His program design insight and expertise has allowed us to develop a very user friendly tool. He is an excellent communicator and has been able to understand our programming needs based on design sessions, and implement those ideas into COMFEN. COMFEN is easy to use, but under the hood it is quite complicated, calling many sophisticated calculation engines “behind the scenes”, and yet it produces results that are easily understood by the target audience, which is primarily architects who are trying to digest complex information to make good design decisions. His attention to detail as well as the ability to see the “big picture” allows him to produce an excellent software tool. He has been wonderful to work with and hopefully we will be able to continue to work on our projects into the future.”

Robin Mitchell
Windows and Envelope Materials Group
Lawrence Berkeley National Labs

“Daniel McQuillen is a superb programmer. We are very pleased with his work on a complicated project. We recommend him highly, and would be pleased to work with him again!”

Joe Deringer
The Institute for Sustainable Performance in Buildings

“The software completed by Mr. McQuillen was sophisticated, user-friendly, and met all aspects of our training needs very well. Perhaps the most impressive work aspect was that Mr. McQuillen could complete such a complex, user-friendly software for us in such a relatively short time frame — he met our tight deadline admirably! I am very pleased to recommend McQuillen Interactive for any interactive design projects, large and small.”

Ted Chira-Chavala, Ph.D.
Institute of Transportation Studies
University of California, Berkeley

“Daniel McQuillen is a Professional. He can come in to a very fast-paced, massively interconnected environment and almost immediately make you feel that he has been there for years. His quality of work, ease of managing, and timeliness makes him quite an asset.”

Isaac Epp
Director of Development
Vitesse Learning