Oleg Ilyenko, author of Sangria, talks about his experience implementing the GraphQL specification. He discusses concepts like query analysis and introduces different instrumentation ideas. The slides can be found here.
More and more GraphQL clients are being developed recently. (Which is fantastic!) Cashay takes a similar route as Apollo and uses Redux internally. It also comes with Webpack support baked in. Let us know if you already tried it.
Sangria seems to be one of the most actively developed GraphQL server implementations. Last week a new version landed with many great improvements and spearheading the GraphQL CATS project (Compatibility Acceptance Tests).