To be sure, the move toward regional autonomy was also chaotic, blighted by the convictions of dozens of regional leaders for corruption.

Mr. Joko, however, is a notable example of its success. Born in a riverside slum in the Central Java city of Surakarta, the 53-year-old craftsman was twice elected mayor and used his election as governor of Jakarta in 2012 to catapult himself onto the national political stage.

He will be the first president in Indonesian history not to have come from its Suharto-era political elite or to be a former army general, and the first to assume the presidency having experience running a government.

He will be sworn in on Oct. 20 in a ceremony to be attended by the departing president, Susilo Bambang Yudhoyono, who was constitutionally barred from seeking a third term. Such a tableau has never been seen in Malaysia, Cambodia or Singapore.

Simon Tay, chairman of the Singapore Institute of International Affairs, said the notion of handing over power to a political opposition had become an alien concept in those countries because their respective leaders and governing parties had been in power so long.

“It’s the whole establishment, and they are not used to anything else,” Mr. Tay said. “The nature of political change would be very sweeping, and there is a fear that their countries as they know them would not survive.”

Indonesia has proved that this does not have to be the case.

The first years of democratization were tumultuous, characterized by bloody nationwide street protests, ethnic and sectarian unrest that killed thousands, terrorist attacks by homegrown Islamist militants and reluctance by the country’s feared armed forces to bend to civilian rule. The country’s first democratically elected leader in four decades, Abdurrahim Wahid, was impeached in 2001 after less than two years in office on allegations of corruption and incompetence, after tense political battles with his rivals in Parliament.