During the fellowship, I learned how to validate more effectively, especially by using filters, search functions, and setting up map paint styles. I became better at identifying issues, mapping across different countries, and validating data from other regions. This helped me understand mapping more deeply, including the different shapes of buildings across countries. I also gained a stronger grasp of quality standards and grew more comfortable using JOSM shortcuts. For example, while validating building footprints in Africa and later in Asia like Japan, North and South America, I noticed differences in building construction styles and settlement patterns. By applying filters and map paint styles, I was able to quickly identify inconsistencies such as overlapping polygons or missing tags and correct them. This experience not only improved my technical validation skills but also gave me a broader perspective on how mapping standards can be applied across diverse contexts.

During my validation mapping in Japan, I encountered a task where the same area had been mapped using two different imagery sources of Bing and Esri. This created alignment issues and inconsistencies in the data. Through the fellowship, I learned how to handle imagery offsets, switch between imagery layers and use search tools to trace a particular mapper’s edits. By applying these skills, I was able to identify the discrepancies, adjust the imagery and improve the overall quality of the map. This experience was particularly meaningful because it showed me how technical validation techniques like managing imagery sources and targeting specific edits can directly enhance data accuracy. It was a proud moment to see how my improved skills contributed to cleaner, more reliable mapping outputs.

One of the challenges I faced during the fellowship was that the training period overlapped with my lectures and exams. At times, I struggled to balance both commitments. However, I was grateful that the recordings were always available as a backup, which allowed me to catch up and stay on track. If I could improve the fellowship, I would suggest adding more flexible scheduling and interactive sessions to help balance learning with other commitments and make more friends.

I am Justine Cyurinyana from Rwanda, proud to be a passionate mapper and humanitarian. My inspiration to join HOTOSM was to make a greater impact, and through this fellowship I have improved my skills, gained confidence in mapping and validation and had the opportunity to train and learn from others. With over 160,000 buildings, 5,000 km of highways and 2,000 km of waterways mapped, I focus on quality over quantity and hope to continue creating meaningful impact through mapping. I am grateful to ESA Hub for the opportunity and especially to Rebecca Chandiru for being an amazing mentor. She was always there to inspire us even in the midst of confusion and hundreds of questions, she responded swiftly and guided us in the right direction. To my fellow fellowship team, you all made this journey possible. I learned from each of you, even in private conversations when I asked questions and received quick answers.

I am proud of the validator I am becoming proud, bold and confident in contributing quality data. I am here to make more impact.