In Catholicism we have the concept of the Magisterium. The Magisterium is the official teaching office of the Church and consists of all the bishops who are united to the Pope. The Magisterium is believed to have the divine authority to declare dogmas and teach doctrine. Once a dogma has been defined it becomes an essential teaching of the faith such that if you don't believe in it and agree with it you cease to be Catholic.
This system works wonders for maintaining doctrinal unity across the entire Catholic church, as it ensures that all Catholics are teaching the same thing, and believing the same thing no matter where they are in the world. (It should be noted that anything which is not dogma is still open for debate, and so there are many areas where a difference of opinion is permitted, however when it comes to essentials everyone is on the same page)
In contrast to Catholicism you have the Protestant system, which is where every individual Christian takes the bible and decides what it means for themselves. The results of this system are complete doctrinal chaos, with Protestant Christians arguing and setting up factions and splitting again and again and again. No two protestant Christians agree with each other completely, even when it comes to essentials of the faith - they can't even agree what the essentials of the faith are in the first place. There is absolutely no unity in this system.
It seems obvious to me that the Catholic system is superior to the Protestant system when it comes to ensuring doctrinal unity. The truth cannot contradict the truth, so doctrinal unity is essential.
I'm wondering how Judaism deals with this situation? When it comes to deciding doctrine/what to believe, how does Judaism do it? Does each congregation listen to their local Rabbi and submit to whatever he proposes for belief? Is there a council of senior Jewish clergy who come together to decide doctrine which all Jews worldwide must believe? Is it considered the responsibility of each individual Jew to study the scriptures for themselves and come to their own conclusions, like in the protestant system I described above?
The reason I ask is because I get the impression that Jews all more or less believe the same thing and agree when it comes to doctrine, but I'm curious how that is possible because you don't seem to have a Magisterium like Catholics do. I understand that back in the day you had the Sanhedrin, and they were sort of like our Magisterium, with the High Priest being kinda similar to our Pope (although without claiming infallibility). Does the Sanhedrin still exist and does it ensure doctrinal unity?