Politico has an article on the challenge facing the USCIS bureaucrats who have to implement President Obama's executive order on immigration. It's divided between emphasizing the size of the challenge (4 million applications) and the lessons learned from handling Obama's 2012 order for the "Dreamers") which was about a tenth of the size.
One thing Politico doesn't mention that Vox has a piece which mentions the role of intermediaries, those who claim to be able to get people what they want from an impenetrable federal bureaucracy. There's some evidence that 40 percent of the immigration "experts" are con-people.
The holy grail for bureaucrats is to design and implement a process which works the first time, which handles almost all the situations, and which doesn't require intermediaries. It's a dream, not a reality.