| Not an exhaustive list, but important differences off the top of my head: - End-to-end search: Algolia's offerings span both front-end (InstantSearch drop-in widgets) and back-end (actual search API). Simple applications can be built without ever talking to Algolia API at all because their widgets do it for you. Atlas is all back-end - just a DB service with FTS on the side; left to you to integrate front-end. - Configuration: Algolia's dashboard GUI is where a lot of the configuration is done. Some configurations are not available at all via APIs. It's relatively simple. Atlas requires more JSON-type configuration entries, and some knowledge of Lucene internals. - Text analysis: Algolia text tokenization pipeline is mostly a black-box but works fine most of the time. It exposes only a few settings like ascii-folding. It's fine for normal dictionary words, but has problems with domain-specific text (for example, people/place names, scientific terms, etc). Atlas exposes many aspects of Lucene's analysis pipeline, but it does require knowledge of Lucene. - Multilingual support: Algolia supports all its features for ~70 languages. Atlas analysis has to be configured separately for each language. - Query syntax: Algolia defaults to simple queries but the API supports a more complex query syntax with boolean operators and such. Atlas has its own JSON query DSL that's related to Lucene's query syntax capabilities. - Faceting: Algolia faceting configuration and API are far simpler than Atlas's DSL. |