Some interesting things about the community of immigrants/refugees who escaped the Portuguese Inquisition and found a home in Amsterdam in the 1600s:

1. Portuguese Jews weren’t distinguishable from their Christian neighbors in ways that their Ashkenazi brethren were. Like the Dutch of the day, the men wore their beards trimmed, and both men and women dressed in the same fashions as their Christian neighbors. However, the Portuguese community often didn’t speak Dutch very fluently, though they were more likely to be conversant in French, unless they engaged in regular business with their Dutch neighbors.
2. As the refugees arrived in Amsterdam, many began practicing Judaism for the first time in their lives. It had been prohibited in the other places where they had lived before. For the men, this meant undergoing the practice of circumcision, no matter what age they were — whether an infant or an old man. For some, this proved to be a hurdle. Not only was there the pain to consider, but some believed — falsely — that for as long as they were uncircumcised, they would not be held accountable for not following Judaic law.
3. Speaking of reJudaization … the Portuguese community had to import rabbis who literally had to teach them how to be Jews again, and this sometimes led to conflicts. For instance, the venerable Rabbi Saul Levi Mortiera ruffled feathers when he insisted that Jewish relatives who had forsaken Judaism under duress of the Inquisition and who had agreed to adopt Christian ways were cut off from the nation of Israel. Naturally, families who were still missing cousins left behind and mourning those killed in the auto da fé saw this quite differently.
4. As decades went on, more Ashkenazi Jews arrived in Amsterdam. You might think that they would blend in with the Sephardic Portuguese community, but that was far from the case. In fact, there was quite of bit of enmity between the two. There is a record of people being expelled from the Portuguese community by a writ of cherem for buying meat from the Ashkenazi rather than the Sephardic butcher.
5. As we’re talking about cheremim — Baruch Spinoza’s might have been the most famous, but he was far from the only one to be expelled. They were handed out like candy on Halloween. For going to the wrong butcher, as mentioned above. For posting unflattering handbills about a rival. For adultery. For causing a scandal. Nearly always, the bans were meant to be temporary — a sort of time out.
6. To some degree, there were attempts by some members of the community to return to Spain and Portugal to reJudaize their family members or to beg them to leave for Amsterdam. This was incredibly risky as the Inquisition was still in full force, and if caught, they risked not only their own lives, but the lives of anyone they were trying to influence. However, the extent to which this happened may be unknown, as this rejudaization was a big fear among the Christian community of the Iberian Peninsula, and writers of the day there may have exaggerated it. Still, there are accounts from Jews in Amsterdam of people going to their homeland on business and hoping to “free the captives” along the way.
7. Amsterdam may have been an incredibly open home to Jewish people in its time, but the welcome mat only stretched so far. The city’s famous guild system was closed to Jews, meaning that the vast majority of professions were off limits. Newer careers that were opening up at the dawn of the modern age, however, presented opportunities. These included sugar importing and refining, the trade in luxury goods and book printing.
8. Likewise, the city passed laws putting some limits on the freedoms of Jews in Amsterdam. There was no ghetto that existed in other cities, no special tax levied, nor distinctive clothing they were made to wear. But Jews were excluded from becoming burghers (full citizens), were not allowed to debate against Christianity with Christians (though Rabbi Menasseh ben Israel famously did so) and were forbidden to have sexual relations with Christian women (but that happened anyway).
9. Eager to keep the peace, the leaders of the Jewish community policed its members to keep a low profile. It forbade costumed parades on Purim, for instance. And some argue that it zealously punished Spinoza with excommunication in order to demonstrate to Christian Amsterdam that the Portuguese community did not tolerate an “atheist” in its midst.
10. One of the main tasks of the mahamad, the leadership council of the Portuguese community, was how to handle poor members of the community. There were several societies that people were expected to contribute towards – the Dotar which gave dowries to orphaned girls, the Aby Jetomim orphanage for boys, finta taxes for the care of the community. When the volume of poor refugees got to be too great, and the demands on the community overwhelming, the solution was to ship as many people as possible to other destinations — either to smaller cities in the Netherlands or to literally SHIP them to colonies like Surinam or Curaçao. 

Source: Bodian, M. (1999). Hebrews of the Portuguese nation conversos and community in early modern Amsterdam. Bloomington: Indiana University Press.