Most software founders say they listen to customers. Oliver Belin can put a number on it.
“I would say 80% of our solution was built based on input requests,” says Belin, founder and CEO of Miami-based Calculum. “Problems which became opportunities from our clients.”
He made the point in an interview with Procurement Magazine.
What Calculum Does
Calculum is an AI-powered platform that helps organizations free up cash by optimizing when they pay suppliers.
The idea is plain. Payment terms are a lever. Pay too early and cash sits idle. Pay too late and a supplier suffers.
Calculum uses AI to find the right timing across a company’s whole supplier base. MAIN profiled it in 5 Miami fintech AI firms rewiring how money moves.
The company works from a downtown Miami office. It began in 2020 as a spinoff of Switzerland’s University of St. Gallen.
Procurement is not glamorous. It is also where a large share of a company’s cash goes every month.
That makes small improvements valuable. A few days of timing, repeated across thousands of invoices, adds up to real working capital.
Why He Left the Big Banks
Belin has spent more than two decades where finance meets technology. He sold his first company to Macquarie Bank.
He then worked for large banks in London. It did not suit him.
“I would rather work in a small environment where you can create something, you can work with a team, and you can be creative,” he says.
That preference shapes how he hires. He is not looking for a degree.
“Do you have the passion? Do you want to change something?” he asks. He wants people willing to travel, meet clients and keep asking what can improve.
He mixes young graduates with senior leaders. The graduates bring drive. The seniors bring experience.
Belin also teaches the subject as an instructor at the New York Institute of Finance.
His leadership rules are short.
Give people space, and trust them.
Then explain the why. “Not just explaining the problem but the solution,” he says.
He treats trouble as raw material. “Every problem is an opportunity.”
Why Handshakes Still Matter in AI
The surprise in Belin’s story is how little of it is technical. He argues that supplier and buyer relationships still run on conversation.
His advice is to keep a constant dialogue. Then act on what clients say.
He also pushes for real meetings. Many of Calculum’s new clients arrive through people who moved from one customer to another.
“It’s having those personal relationships, which I think is very important in today’s AI world,” he says.
That fits Miami, which hosted the Sibos banking conference for the first time this fall. Finance still gathers in person to talk about AI.
Belin’s story is a reminder that software is sold by people. Trust travels through introductions, not just product pages.
Calculum’s lesson is old and simple. The best AI product still starts with a customer who is willing to say what is broken.
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