About IBM Cloudant
IBM's fully managed JSON document database, built on Apache CouchDB.
Cloudant started as Cloudant Inc., founded in 2008 by Alan Hoffman, Adam Kocoloski and Michael Miller out of the MIT physics department, with seed funding from Y Combinator. IBM announced the acquisition on 24 February 2014 and closed it on 4 March 2014, folding Cloudant into IBM Cloud as a fully managed JSON document database. The engine is based on the Apache CouchDB project and the BigCouch fork, which Cloudant donated back to Apache in 2016 to become CouchDB 2.0. Data is stored as schema-free JSON documents in databases, addressed by a document ID, and served over an HTTP/REST API that any language with an HTTP client can talk to.
Cloudant follows a master-less cluster model: every node accepts writes, and the same multi-master replication protocol that powers CouchDB and PouchDB sync handles the reconciliation. That makes it the default operational store for offline-first mobile apps, web apps and IoT devices that lose the network and reconnect later. On the indexing side, Cloudant ships MapReduce views for secondary indexes and aggregations, Cloudant Query for declarative JSON queries, Cloudant Search backed by Apache Lucene for full-text, and a geospatial index for location queries. The trade-off the IBM docs themselves call out: Cloudant is built for document operations and known access patterns, not for ad-hoc cross-database analytics. That is why most teams pair it with a warehouse: the live documents stay in Cloudant, and a sync (via the _changes feed or scheduled extracts) makes the same data joinable in SQL alongside the rest of the business.