In October 2025, as Hurricane Melissa bore down on the Caribbean, a team of data scientists at the United Nations Office for the Coordination of Humanitarian Affairs (OCHA) in The Hague was already at work. Anticipatory action frameworks had been triggered in Haiti and Cuba, and the team was comparing forecasts against past storms to estimate the impact. Observing their work was Davide Longo, a Network Science PhD student from NetSI London’s Complex Connections Lab, only a month into his internship at OCHA.
“I saw how the work of a data scientist can make a real, concrete difference in supporting those who have to make decisions and coordinate aid during a crisis,” he recalls. It was a moment that stayed with him, reconfirming that data doesn’t just sit in a paper, but helps people act in a moment when time can be of essence.
Davide joined the OCHA's Centre for Humanitarian Data and its Data Science Team, led by Leonardo Milano, from September to December 2025, after spotting the role on the UN Careers Portal and making it through technical assessments and interviews. He started working on HDX Signals, the Centre’s early-warning tool for humanitarian crises. Every day, the platform watches data on conflict, displacement, food insecurity and market prices across around 200 locations. When something shifts significantly, it sends out an alert with a short AI-generated summary, giving organizations a head start on emerging crises.
Rather than working on one small piece, Davide built new features for the platform in R across nearly the whole pipeline, from the logic that detects significant changes in the data, to the AI summaries and the final reports. For Davide this was an eye-opening experience, “It gave me an inside view of how a real-world system that automatically collects, integrates and processes data from multiple sources every day actually works, and of what it means to write code that runs in production.”
His second project with OCHA took him to the frontline of anticipatory action. Working on an application that monitors flood exposure across several African countries, Davide developed and validated a data-driven method to improve how exposure severity is classified. By accounting for historical and seasonal flooding patterns, his approach will help humanitarian operators spot periods of heightened risk and direct aid where it’s needed, before the water rises.
Just as valuable as the projects was working in an environment so different from academia, where, Davide notes, you often work fairly independently. At the UN, nothing happens in isolation. The Centre is constantly collaborating with other agencies, and “every task is part of a much larger project involving multiple teams and different levels of the organization.” He calls this contrast one of the most formative parts of the whole experience.
Back in London, these lessons remain valuable. Davide’s PhD, supervised by Prof. Riccardo Di Clemente, uses network science to study health equity in cities: how where we live shapes our health, or in other words the social determinants of health. While his research is independent from the internship, his time in The Hague showed him how closely these questions connect to the UN’s mission, especially as more of the world moves to cities and urban inequalities become one of the defining health challenges of our time. Working with humanitarian data has also pushed him to think about more vulnerable contexts, where the link between place and health is even more urgent.
“Cities are complex systems,” he says, “and network science offers valuable tools to study how neighborhoods, mobility, access to services and living conditions are connected and influence people’s health. I believe there is great potential in bringing these methods into the work of international organizations, and I would like my research to help build that bridge.”
As for what comes after the PhD, Davide is keeping his options open, confident that the skills he’s building can make a difference in academia, industry or international organizations alike. Wherever he lands, he’s already seen what’s possible when science and humanitarian action meet.
