When managing SEO across multiple countries and languages, I measure success by tracking key metrics such as organic traffic, keyword rankings, conversions, click-through rates, and user engagement separately for each region and language. I use dashboards and reporting tools to segment data by country, market, and language, making it easier to identify trends and compare performance across different locations. Regular reports typically include visibility growth, top-performing keywords, landing page performance, conversion data, and insights into regional opportunities or challenges. By presenting both overall international performance and market-specific results, stakeholders can clearly understand the impact of SEO efforts, evaluate ROI, and make informed decisions about future optimization strategies in each target market.