Currently, What technology OneMap use for Map Service?

According by GeoWorks today 06/Sept/2019, I understand that
OneMap is currently not base on esri technology and rely on opensource technology.
So, may I know which technology OneMap use to create fast and beautiful map service?
How to styling the map layers, how to host map service to get map tiles image faster and how to calculate map routing?
I’m really interest on this, you guys are very professional!

Hi @MinChanSike, thank you for your time attending our Singapore Geospatial Week. I can forward your request (cc your current registered email address in here) to our Product and Project Team if we can able to share on this technical insights. In the email, we also would like to know more about you and/or your company.