SÃO PAULO, Brazil — It was a cherished ritual that Joyce Fernandes saved for the end of the shift of a job she despised.

After finishing tidying up every other room in one of the São Paulo apartments she cleaned, Ms. Fernandes took her sweet time dusting a bookshelf in the living room, where she inevitably got lost in a book.

She feared she would get a stern talking to when the apartment’s owner walked in one day in 2008 as she was devouring “Olga: Revolutionary and Martyr,” a biography of a German communist militant who spent years in Brazil before being executed by Nazi Germany.

Instead of a reprimand, the moment spurred a remarkable career transition for Ms. Fernandes, who is now among the highest-profile Black Brazilians, driving candid conversations about racism and inequality.

The employer, after hearing Ms. Fernandes talk about her passion for history, encouraged her to enroll in college. She did. She earned a degree in history in 2012, and has since developed a large following as an Instagram personality and a rapper, written a book about the lives of Brazilian maids and become a television host.

Her multifaceted career and rising profile sometimes feel like a mirage, she says, when she recalls how most of her early employers dismissed her aspirations.

“They always said there was no point in getting an education,” said Ms. Fernandes, whose stage name is Preta Rara, which means unique Black woman. “They said I was predestined to serve, just like my mother and my grandmother, and that I should be happy with what was already predestined.”

Preordained her future was not.

Ms. Fernandes, 35, remembers a cloistered childhood in Santos, a coastal city in the state of São Paulo. Her mother, also a maid, and her father, a mailman, mostly kept their four children inside, fearing they could get drawn into the criminal activity that was pervasive in their neighborhood.

“I tend to say that I was raised by Brazilian television,” Ms. Fernandes said. “It was the only form of entertainment we had living in a marginalized area.”

Spending countless hours watching soap operas and variety shows gave Ms. Fernandes her first window into Brazil’s rampant racism, which became the dominant theme of her work as an author and an artist.

“You didn’t see Black people being well represented,” she said. “I would only see people like me in the role of slaves or maids — people in the margins.”

After graduating from high school, Ms. Fernandes saw racism through a different lens when she set out to find work in sales or as a receptionist. She started receiving calls for interviews only when she reluctantly followed a piece of advice offered by a Black career coach: Never send out résumés with a photo.

“I sent out my résumé without a photo, and the next week I was flooded with calls to come in for interviews,” she said. “That’s when I realized just how cruel Brazil can be for Black people.”

None of the interviews led to offers. After a few months, feeling dejected, Ms. Fernandes followed in the footsteps of her grandmother and mother and began picking up shifts cleaning homes.

“When I got home and told my mother that I had found work cleaning for a family, she was very sad,” Ms. Fernandes said. “She knew I would soon experience the things she went through.”

At several of the homes where she worked, Ms. Fernandes said, she was not allowed to eat the food she prepared, entitled only to leftovers. She was barred from using certain bathrooms and had to use the elevator marked for “service” and steer clear of the one for “social” visits. She was given stained and tattered clothes as hand-me-downs.

“Employers think of you as their private property, like you’re an object that belongs to them,” she said.

The indignities of those years haunted Ms. Fernandes long after she stopped cleaning houses and found work as a high school history teacher. The memories were weighing on her one day in June 2016 when she posted a couple of anecdotes on Facebook. The post was meant to share a few painful memories with friends, but it soon prompted a cascade of responses.

Thousands of former and current maids created posts of their own using the hashtag #I’mAMaid. Several disclosed being sexually harassed on the job. The volume and rawness of the responses compelled Ms. Fernandes to record first-person accounts in a book published in 2019.

It begins with the story of her grandmother, Noêmia Caetano Fernandes, who began working as a maid at 14 and remembered being fed only after everyone in the family had finished eating.

The second account, by Ms. Fernandes’s mother, Maria Helena da Silva Fernandes, is among the most harrowing in the book. The elder Ms. Fernandes was effectively abducted as a child by a family that promised to pay for her education and meals but instead forced her into servitude.

“I was forced to sleep in a little wooden box next to the dog kennel,” the mother says in the book. She was rescued the day she menstruated for the first time. She was home alone and screamed at the sight of blood, which prompted neighbors to call the authorities.

Ms. Fernandes, the mother, began working as a maid at 17. She remembers one boss who treated her warmly, becoming a motherly figure, and others who humiliated her. “The only trauma that remains is not having learned how to read and write,” she told her daughter.

The book generated plenty of news media coverage and invitations to appear on television shows and podcasts. Ms. Fernandes’s goal was to remind Brazilians of power structures that many choose not to reflect on but are intimately familiar with.

She said she intended the book to be a difficult read.

“I believe that by making people feel uncomfortable is the only way things change,” she said.

According to a 2019 government report, the overwhelming majority of Brazil’s estimated six million domestic workers are Black women with few years of formal education. Maids work 50 hours per week on average, and their median salary was 92 percent below the minimum wage.

Benedita da Silva, one of Brazil’s few Black female lawmakers, also worked as a maid early in her career. She credited Ms. Fernandes with blending art and activism brilliantly to raise awareness about labor abuses and racism.

“As an artist she reaches a slice of the population, the middle class, where public opinion is shaped,” Ms. da Silva said in an interview. The book, Ms. da Silva said, struck a raw chord. “Often, only after people read the book do they realize they are perpetuating these situations.”

After the book was published, Ms. Fernandes’s following on Instagram, her preferred social media platform, exploded. To her more than 166,000 followers, she comes across as raw and unscripted in videos and posts that she devotes hours to curating.

She talks about serious issues like police brutality and sexual abuse. She speaks with pride about coming to love and celebrate her body, which doesn’t fit the Brazilian bombshell stereotype.

The traction she gets on social media helped Ms. Fernandes land a television gig last year hosting a talk show on Globo, the country’s largest cable network. Yet that mainstream platform hasn’t led her to change her style or modulate her message.

“I was invisible in this society for too long,” Ms. Fernandes said, before flashing a smile. “So now everybody has to soak up my delightful figure wherever I happen to be.”