Singapore today is in every way as multi-cultural as Thailand from a white person's perspective, just with more rules.
As a foreigner, you are categorized in three buckets (citizen, permanent resident and other - the latter can be tourist or tax paying employee with visa) plus your race. The three buckets determine, which price you pay in anything that is public service or health care (3-tierd pricing in SG vs. 2-tierd pricing in Thailand).
To become a permanent resident (or citizen) in Singapore you have to strengthen the ethnic status quo and cohesion of society. On your first visa application you state your race and you're categorized accordingly. Singapore is majority ethnic Han-Chinese, followed by Malay and Indian. Whites are a single digit percentage. Accordingly, if you want to become permanent resident nowadays as an employee on Employment Pass coming from Mainland China working eg. in one of the 'Singaporean', mainland Chinese founded tech companies (or also any other respected company), you'll easily get it after completing your first round of full year taxes about 1.5 years in.
These days, as a white person, you won't get it even after living and working in Singapore for 10 years on an Employment Pass. Forget about ever being able to retire in Singapore, even if you buy property at the inflated 60% stamp duty you have to pay as someone who just works there, but is not considered a permanent resident. After ending your job, you are a tourist and are required to leave.
You will never become a permanent resident or citizen in today's Singapore, unless you're a billionaire trying to evade US taxes. Then they do grant you citizenship, since that is the one and only exception (i.e. bringing lots of money to Singapore, in the 100m USD range and up).
Mind you, things in Singapore have changed massively in this regard since the immigration wave of about 2009. It's one of the most xenophobic countries I've ever been to so far (as a white person, admittedly). It's also a very friendly country, as long as you know your place. You'll just never be part of it. Singapore in this sense is very, very Southeast Asian.