search

Binary search is easy to describe and famously easy to get wrong (off-by-one, infinite loops). The signal is a correct template plus the variants (boundaries, rotated arrays) that come up constantly. Here is the answer.

E-commerce search is where retrieval, ranking, and business goals collide, and it carries a hard exact-match requirement (brand, size, SKU). The signal is query understanding plus hybrid retrieval plus business-aware ranking. Here is the design.

Query understanding is the front end of search that turns a raw query into structured intent. Get it wrong and even a perfect index returns garbage. The signal is the pipeline and how you measure it. Here is the design.