If Rails is omakase, Japanese construction and IT projects are marunage.
When I first heard about the popular readout and the written article of Rails is Omakase, I immediately thought about another common Japanese word called marunage 丸投げ (pronounced mah-rue-nah-gay), which literally means passing everything onto someone else and completely getting rid of the things which you passed onto.
The actual usage of the word marunage is more vicious and exploiting; large corporations and government organizations often do the marunage to their contractors. When you do the marunage of a project, it means you are getting rid of all the responsibilities and liabilities from the project and letting someone else take care of the mess and the aftermath. In this sense, marunage is a form of risk dumping, or simply a bad form of delegation. The analogy of marunage is also quite common for the national projects. For example, the ministries do the marunage to the research subsidiaries.
I believe the word marunage originally comes from the construction industry, which is very popular in Japan for multi-level delegation from a large general contractor aka zenekon ゼネコン (pronounced zeh-neh-con) to the smaller and powerless contractors aka shitauke 下請け (pronounced shi-tah-ooh-keh). The business model here is that the shitauke companies do the most if not all the actual tasks, and the zenecon does little things other than taking brokerage fees. Multi-level sub-contracts are also popular; for example, in Fukushima Dai-ichi Nuclear Power Plant cleanup project after the meltdown incident on March 2011, ten levels of sub-contracts were revealed.
The mindset of zenekons enslaving the shitauke companies is also common in IT industry in Japan. The IT zenekons, also known as shisutemu integureitaa ("systems integrator" aka "SIer"), have been historically accused of making questionable practices on winning large-scale project contract bids, such as winning a contract by proposing unrealistically budget. For example, in 1989, there was a case of major SIer repetitively tried to win bids by proposing one (1) yen (JPY) as the budget for a whole project of municipal governmental systems. Also, those large SIers or IT zenekons maintain strong relationships with the large-scale customers, and gain profits by doing the marunage of the projects to the shitauke companies. I won't dig deeper in this dark side of Japanese IT history here, but you may find many similar cases.
Getting back to the definition of marunage, I believe that the mindset of marunage represents the feverish risk-aversion towards everything among Japanese people. Still many if not most workers in Japan think a single failure means the professional death which cannot be recovered later, and the legal and economic systems are very harsh against people who have the failure records, for example, a bankruptcy. This kind of culture forces the decision makers to do the marunage to avoid risks. And I see the culture of marunage shows how Japan is more and more closely like the former Soviet Union, one of the most bureaucratic and stagnated nations, disbanded by the economic failure.
So when you hear about marunage, you've got to be very careful; don't become the victim, and try your best to avoid becoming an oppressor by doing the marunage to the powerless subordinates, colleagues, coworkers, or even your family members or bosses.