Day 89 of Learning MERN Stack

During days 89 and 91 of a 100-day MERN Stack engineering run, the developer advanced through complex SQL challenges on HackerRank. The focus shifted from standard LIKE operators to REGEXP and String Anchors for textual pattern recognition. Further progress included mastering NOT REGEXP exclusion operators, CONCAT() for dynamic formatting, and advanced GROUP BY structural analytics. These skills enable efficient data pipeline processing and enterprise backend reporting, such as generating automated system summaries directly from the database tier.