This is fascinating stuff — every time I use my oyster card I have wondered what it is doing behind the scenes. Do you know of any write ups about TFL's infras

This is fascinating stuff — every time I use my oyster card I have wondered what it is doing behind the scenes. Do you know of any write ups about TFL's infrastructure/processes? Would love to read about it. I'd also like to buy whoever lead the TFL API's move from XML to JSON a coffee|beer!