In general, as a Neo4j Labs project, neo4j-graphql.js is being actively worked on, and might still be a bit rough around the edges. Therefore, we don't provide official commercial support for these projects or guarantee longevity. However, some Neo4j customers and users still love the functionality of these projects and choose to continue using them in production environments. Ideally, a Neo4j Labs project graduates and moves into an officially supported project at some point.
More specifically, there are still some features in neo4j-graphql.js that we need to implement, next on our list are support for filtering, better handling of union and interface types and how they relate to node labels in Neo4j, and generating type definitions from an already existing Neo4j database. So if your use case relies on these features, then it might be best to wait a bit for these to be built out.
Having said that, some companies are indeed using neo4j-graphql.js in production. For example, the Financial Times uses neo4j-graphql.js to power their "biz-ops API". Rhys Evans, Principal Engineer at the Financial Times recently gave a presentation at GraphTour London about how they leverage neo4j-graphql.js and GRANDstack, you can find the slides here - "A field guide to the Financial Times". I am aware of others using neo4j-graphql.js and GRANDstack in production, but I won't call them out here ;-)
Maybe others could chime in? Are you using neo4j-graphql.js / GRANDstack in production? Tell us about it in this thread.