The scientific aspects (algorithms, incl. implementations, performance evaluation) of Web crawling (including focused crawling) is covered by conferences like WWW, ACM SIGIR, BCS ECIR, ACM WSDM and ACM CIKM.
But you may refer to informal MeetUps or trade fairs; if so, google "Web Data Extraction Summit", "OxyCon Web Scraping Conference", "ScrapeCon 2024" (all past) or the forthcoming: https://www.ipxo.com/events/web-data-extraction-summit-2024/
But you may refer to informal MeetUps or trade fairs; if so, google "Web Data Extraction Summit", "OxyCon Web Scraping Conference", "ScrapeCon 2024" (all past) or the forthcoming: https://www.ipxo.com/events/web-data-extraction-summit-2024/