PERSONAL STYLE OR CANNY STRATEGY?
Some observers say Abiy, a former military officer specialising in cyber intelligence, will sometimes bypass ministries because his reforms must maintain their breakneck momentum or become mired in bureaucracy.
Those reforms - including unbanning political parties, releasing imprisoned journalists and prosecuting officials accused of torture - have drawn ecstatic crowds at rallies.
"Abiy seems to have relied on his charismatic rule," said Dereje Feyissa, a professor at Addis Ababa University. "The question is whether this is sustainable. Euphoria is subsiding."
Other observers say Abiy's rapid changes are a deliberate attempt to wrong-foot opponents from the previous administration, which was dominated by Tigrayans, a small but powerful ethnic group.
Abiy, 43, is from the Oromo group, the nation's largest, which spearheaded the protests that forced his predecessor to resign. Since taking office in April 2018, Abiy's government has arrested or fired many senior officials - mainly Tigrayans - for corruption or rights abuses.
"In the first six or seven months, he undercut the institutions ... The institutions were either not working or working against his agenda," said Jawar Mohammed, an Oromo activist and informal adviser to the prime minister.
"I don't think he could have travelled this far without doing that."