Platform ecosystems have become an organic part of the economy and a weekly routine for a significant number of consumers. The purpose of the article is to analyze the structure and features of platform ecosystems development on the example of four largest Russian platform ecosystems (Sber, Yandex, Wildberries and OZON). The article uses the methods of comparative analysis, generalization and synthesis. The article is based on the data of financial statements of Russian marketplaces as parts of platform ecosystems, data in the open press and official websites of companies, corporate reports of the studied companies. The study finds that Russian national platform ecosystems began to develop actively later than their global competitors during the pandemic, because before that they often faced problems with trust and interaction with users. Network effects play a key role in the effectiveness of platform ecosystems in Russia. Achieving and maintaining these effects can be challenging due to market fragmentation and different levels of digital literacy in different regions. Russian platform ecosystems depend significantly on the chosen business model for their financial performance. Some are interested in the introduction of modern technologies and are willing to incur losses, others choose a strategy of cost minimization, shifting all sorts of penalties to their participants, while others promote themselves at the expense of their personal brand and customers’ trust in them. The results of the study can be used in cross-country comparisons of platform ecosystems and to capitalize on their positive experiences in the future.