Guardian Cities is in São Paulo for a week of live reporting and special events, discussing every aspect of this fascinating Brazilian metropolis. While its flashy yet much smaller sibling Rio de Janeiro does its best to hog the spotlight, it is São Paulo that is now flexing its muscles as South America’s first true megacity – a bustling metropolis of nearly 20 million people, home to incredible creativity and thriving commerce, but also some uniquely eye-opening social problems.

From the open-air drug market known as “Crackland” to the 8,000-strong tent city for homeless people, this is a city with open wounds. Meanwhile, the rich skip the legendarily bad traffic in helicopters to and from their wealthy gated communities, closed off from the poorer communities of the suburban periferia.

Above all, however, São Paulo is a hustling city, the engine of Brazil, where Brazilians and foreigners alike – including the world’s biggest expatriate Japanese community – come to seek their fortunes. If some migrants end up in slavery conditions selling sweatshop wares at the secretive and dangerous “Little Night Market”, where Guardian Cities gained access for a special report, luckier ones find their way into the city’s buzzing art world and top-notch restaurant scene.

Whether you live in São Paulo or further afield, we hope you’ll get involved with our reporting this week.

For starters, join us as we kick off on Monday 27 November by reporting live from São Paulo’s politically controversial “occupations” – abandoned buildings taken over by people who can’t afford a home.

Follow us on Facebook, Twitter and Instagram, contribute to the conversation using #guardiansaopaulo and email saopaulo.week@theguardian.com with your comments, criticisms or suggestions.

Thanks to those of you who responded to our callout earlier this month – we’ll be publishing a wrap of your responses at the end of the week.

With all the energy, strife and potential of 1980s-era New York City, São Paulo is the new urban powerhouse of the southern hemisphere – a city that has at long last made itself unignorable. We hope you’ll join us.