My strategy for suggesting trending topics on a News app would involve several steps. Initially, to identify trending topics, I would assess both the frequency and recency of their appearance in articles, as well as the level of social media engagement surrounding them. An algorithm could be created to rank these topics according to these criteria. Next, the personalization of topics would be a key consideration. I would develop a system that monitors the user's reading habits, search queries, and interactions within the app. This data can be utilized to train a classifier, enabling tailored recommendations for individual users. To maintain scalability, I would explore technologies such as Apache Kafka for real-time data streaming and Apache Hadoop for distributed data processing. Additionally, AWS services like EMR and S3 could be employed for both computational tasks and storage solutions. Lastly, to evaluate the effectiveness of the recommendations, we could analyze metrics like click-through rates (CTR) and conversion rates, allowing us to continuously refine the algorithm based on these insights.