A new constitution will not solve Peru's problems.
The Dominican Republic has had 32 constitutions, a world record. The United States has had one two [I forgot about the Articles of Confederation when I was first writing this]. The DR has a GDP per capita of $8,476.80. The US GDP per capita is $70,248.60, almost 9 times higher. The Dominican Republic is ranked 68/100 on the Freedom House Index. The US gets an 83/100. The higher the score, the freer the country. Surely, if writing a new constitution every six months improved economic and freedom indices the DR would be freer and more developed, while the US would be poorer and unfree. In fact, the opposite seems to be true: greater constitutional stability leads to less chaos, greater freedom, and more economic development.
It's not that Dominicans are incapable of creating a prosperous and free country. Yes, their culture is different being mainly of Spanish, African, and Native Caribbean extraction. But a similar cultural and ethnic admixture is found in many parts of the US, and indeed other Caribbean islands which are more highly developed and enjoy greater political freedoms. What populists fail to understand is that a constitution is only as effective as the people who enforce and respect it.
A constitution is a general framework, often worth the paper it's written on without a serious commitment from all institutional actors to respect what is on it. And what's on it should be: as little as possible. Basically a common commitment from across the political spectrum to economic and political freedoms. The details of day-to-day policy, whether to increase taxation in order to help the poor or reduce it to induce economic development, should be up to a popularly elected parliament.
Peru's problems stem from endemic corruption, from the political class down to beat cops. This cannot be solved by electing a constitutional convention and spending a year discussing whether the new constitution should have a clause asking the Spanish King to apologize for the destruction of the Inca Empire 500 years ago. Yes, its semi-presidential system as currently set down gives too much power to Congress when it comes to the impeachment of the President and her cabinet. But fixing this should be done through an amendment process, not by starting from scratch.
To tackle corruption improve the security services, the prosecutorial service, and the judicial system as a whole. Pay beat cops and prison officials more so that they stop asking for bribes at traffic stops and stop forming part of prison criminal gangs. Prosecutors and investigative judges should be well paid and protected. They should be thought of as the tip of the spear in the battle to tackle corruption at all levels of government. Likewise judges should be free from intimidation and political meddling.
Doing these things does not require a new constitution. It may require amending the current one, but that process should be less fraught and divisive than what the Venezuelan-inspired radical left wants to do. A constitution is like a supermarket shopping list: eventually you'll end up in your kitchen with all of the ingredients for your meal, but you'll have to put in the time, effort, and maintain the peace once everyone sits down to eat it.