The document discusses building effective APIs with GraphQL and Absinthe. It covers topics such as preventing overfetching with GraphQL queries, implementing efficient pagination with Relay Cursor Connections, inserting and mutating data with mutations, real-time capabilities with subscriptions, handling errors, versioning schema with deprecations, limiting query complexity, and tools for building GraphQL APIs like GraphiQL and GraphQL Playground. The document provides learning resources and links for documentation, books, and example projects using Absinthe for GraphQL APIs in Elixir.

1. Craft effective API with
GraphQL and Absinthe
by Ihor Katkov

2. WHO AM I?

3. N+1 issue
GET /coins?limit=10&start=0
GET /coins/btc
GET /coins/btc/history
GET /coins/btc/exchanges?page=1&limit=2
GET /exchanges/binance
GET /exchanges/kuna
“GraphQL prevents HTTP overfetching”

4. GraphQL prevents HTTP overfetching
QUERY RESULT

5. Stop! We can include all the info into one payload!

6. What about a pagination?

7. What about a pagination?
Answer: Relay Cursor Connections

8. EFFICIENT PAGINATION
QUERY RESULT

9. EFFICIENT PAGINATION
QUERY RESULT

10. EFFICIENT PAGINATION
QUERY RESULT

11. YOUR FRONTEND TEAM GUY GONNA SAY

12. INSERTING DATA?

13. MUTATIONS

15. SUBSCRIPTIONS

16. EFFICIENT REAL-TIME
QUERY RESULT

17. WHAT IF… ERRORS?

18. COMPILE-TIME ERROR

19. RUNTIME ERROR

20. WHAT ABOUT ELIXIR?

21. DECLARE AN OBJECT

22. DECLARE AN INTERFACE

23. QUERY ENTRY POINT

24. MUTATION ENTRY POINT

25. SUBSCRIPTION ENTRY POINT

26. RESOLVING IT

27. RETURNING ERRORS

28. VERSIONING

29. AS EASY AS DEPRECATE

30. COMPLEXITY

31. LIMITING QUERY BY COMPLEXITY

32. CUSTOM FIELD COMPLEXITY WITH
DATALOADER

33. CUSTOM FIELD COMPLEXITY

34. TOOLS

35. GRAPHIQL SIMPLE

36. GRAPHIQL ADVANCED

37. GRAPHQL PLAYGROUND

38. ABSINTHE HAS IT ALL!

39. LEARNING RESOURCES

40. LINKS
Documentation: https://hexdocs.pm/absinthe/overview.html
Book:
https://pragprog.com/book/wwgraphql/craft-graphql-apis-in-elixir-with-absinthe
Project example:
https://github.com/ihorkatkov/coinmarketcap-graphql-example

41. {:ok, “THANK YOU!”}
Questions?