Just over two years ago, Baby Angelina Kartiko and Beryl Leomongga, husband and wife owners of Marrickville corner cafe Algorithm, made a life-changing decision. Weeks from returning to Indonesia after living in Sydney, they decided to stay.

“We were selling our furniture, our car, and then something happened,” Leomongga says. “We got something in our hearts.”

Kartiko agrees. “We feel Australia is our home,” she says.

The pair soon spotted Algorithm’s site, an orange-brown brick building that housed a cake shop, and painted it white. They updated and refitted the interior with serious coffee and kitchen equipment, reworked the decor with cool grey tones and drafted staff.

In September 2023, they opened Algorithm, their first cafe. Now, on any day of the week, it is full of customers.

“It’s amazing,” Leomongga says. “We thank god for that.”

Kartiko, head chef with a background of working at Bill’s and Quay, nods. “We serve what we love,” she says. “And that overflows to our customers.”

The menu, which ranges from banana loaf with earl grey caramel butter to roasted spam with egg, chilli aioli and tomato relish on a sourdough English muffin, and green pea and chickpea falafels with butternut pumpkin hummus, cherry tomatoes, avocado, dukkah and green dressing, is pretty thrilling.

“It’s Australian brunch but I also like Japanese fusion, so it has a little Japanese touch,” Kartiko says.

“Our background is Indonesian but we want to blend with the Australian culture. That’s why we serve Australian brunch.”

Kartiko devises weekly and weekend specials. This week’s include a lush prawn roll and a crispy skin chicken caesar roll with fresh corn, crunchy maple bacon, egg and fried shallots on a potato bun.

Kartiko’s French crullers, a signature cinnamon version and today’s special, cookies and cream, are hand-piped each morning. Both are buttery cathedrals of melt-in-the-mouth sweetness.

Other pastries, housed in a slide-out counter drawer, included a dainty canele and a croissant cup (created in collaboration with Stanmore bakery Pastry Story), the latter layered with espresso brownie, orange flan, vanilla cream and shaved chocolate.

If you can eat this without a short food blissdream afterwards, I can’t help you.

Leomongga leads a tailored range of caffeine options using Mecca beans. He holds their Moonwalker blend in high esteem.

“The first time I had coffee in Australia that I love it was Moonwalker,” he says. “That is a classic that never fades.”

Drink it in Algorithm’s zen-like decor, a granite poem to hues of grey. There’s a large round concrete table, a marble-like, aluminium-topped front counter, speckled grey plates and cups and cement-style flooring and walls.

If anyone wearing a primary colour walks in, it’s like fireworks going off in a quarry.

We’re sitting on pale angular stools sipping signature glasses of Rhythm, Algorithm’s cold brew served over ice and topped with orange-zested vanilla cream (without question, the caffeine drink of the summer), while, metres away, cars, buses, bicycles, skateboards, trucks, motorcycles and banking aeroplanes flow by.

Algorithm also excels with its staff, an area Kartiko and Leomongga feel strongly about.

“Everyone that works here, we treat them as a family,” Leomongga says. “We want to make happy vibes so that every time customers come they can feel the happiness inside. It’s not just work here and then go home. We want to invest in them for the future.”

Customers are greeted with great cheer and inquiry. Takeaway orders and tables are swiftly organised. Menus, cutlery, napkins and carafes of water arrive like lightning. People awaiting takeaways sit in specially built seating nooks with adjustable cubes for arm rests.

On this humid late spring morning, three police officers in bulletproof vests order iced raspberry earl grey teas with wildflower honey and vanilla cream.

Kartiko and Leomongga will soon open a second Algorithm in Potts Point on Darlinghurst Road.

“The plan is January but I’m pushing the builder to open in December,” Leomongga says. “We’ll have the classic Algorithm food and drink but with some tweaks.”