Build for ALL of Your Users by Anthony Lusardi (liblab)

Build for ALL of Your Users
Anthony Lusardi, Developer Relations Engineer at liblab

apidays New York 2025
API Management for Surfing the Next Innovation Waves: GenAI and Open Banking
Convene 360 Madison, New York
May 14 & 15, 2025

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Transcript

1. Build for ALL of Your Users Not Just Your Customers
2. Quick show of hands 🙋
3. A little about me
4. This is my dog Asher
5. Iʼve been involved in technical community building since I was a teenager
6. Developer Relations for 7+ years
7. Now @ liblab We turn APIs → SDKs
8. Iʼve worked with a lot of APIs
9. Many of our clients actually design very good APIs
10. APIs are often made quickly
11. Many APIs are simple interfaces to underlying data
12. How their users or userʼs users will use them
13. So what do I mean by that? 🤔
14. Letʼs investigate a specific scenario
15. Disclaimer: Donʼt worry about memorizing this ⚠
16. The Customer (your “userˮ) The Service (and company) Itʼs pretty cool! Yeah, itʼs so slick! But whereʼs the profile photos? Letʼs ask the devs! Yeah! Should be easy! Digging the new app? The Users (actual users) GET /user/{id:string} 200 Response id string name string email string
17. The Service Websockets (for real-time chat) REST (for everything else) ✅ RESTful
18. GET /user/{id:string} 200 Response id string name string email string profile_photo_id string GET /user/photo/{photo_id:string} 200 Response photo_id string user_id string photo_url string GET /group/{group_id:string} 200 Response group_id string user_ids string[]
19. A typical user profile schema GET /user/{id:string} 200 Response id string name string email string profile_photo_id string
20. Photos stored in another database GET /user/{id:string} 200 Response id string name string email string profile_photo_id string FK_users_photos
21. And groups stored in another table GET /group/{group_id:string} 200 Response group_id string user_ids string[]
22. The Customer
23. Theyʼve built a successful group chat app
24. It started off small, quick, simple Itʼs pretty cool! Yeah, itʼs so slick! Digging the new app?
25. And then there was a feature request Itʼs pretty cool! Yeah, itʼs so slick! But whereʼs the profile photos? Letʼs ask the devs! Yeah! Should be easy! Digging the new app?
26. An engineer starts working on a ticket The MIGHTY Engineer Task: Retrieve profile photo for a user
27. And makes a request Task: Retrieve profile photo for a user GET /user/{id:string} 200 Response id string name string email string profile_photo_id string “Why no profile_photo_url?”
28. The docs say to make another request GET /user/photo/{photo_id:string} 200 Response photo_id string user_id string photo_url string “Okay so let’s look at the docs” Task: Retrieve profile photo for a user
29. And gets a resource URL GET /user/photo/{photo_id:string} 200 Response photo_id string user_id string photo_url string https://mybucket.s3.us-east-1.amazonaws.com/user-uploads/images/8ujs0ak1nd.jpg “There it is!” Task: Retrieve profile photo for a user
30. And another request curl O https://mybucket.s3… /user-uploads/images/ 8ujs0ak1nd.jpg “At least they’re using a CDN…” Task: Retrieve profile photo for a user
31. And the ticket is closed. The end. Task: Retrieve profile photo for a user
32. Thank You! 🗂 Anthony Lusardi 🔗 liblab.com ✉ anthony@liblab.com 💬 linkedin.com/in/alusardi 🌲 linktr.ee/tony_codes 🔥 captivate.dev
33. A new ticket! 1
34. “Great work! Just need that done for groups now. Group sizes can go up to 256 just fyi.” “I should have been a dog walker” Subtask: Retrieve profile photos for groups
35. But whereʼs the profile photos? Letʼs ask the devs! Yeah! Should be easy! Get user profile Get photo object Get photo resource Repeat for every group member 3  255 group members = 765 requests getGoupMembersProfilePhotos(groupId); Subtask: Retrieve profile photos for groups
36. So the engineering team starts coming up with mitigation strategies. Subtask: Retrieve profile photos for groups
37. “Scour the docs!” “Skeleton loaders!” “Feature request!” “Simulations!” “Make groups smaller!” “Async will save us!” “Edge cases?” “New API provider?” Subtask: Retrieve profile photos for groups
38. So how do we avoid this?
39. Build for ALL of your users,userʼs users, and userʼs userʼs users
40. Architect with intent ✅ RESTful (of course) ✅ API & Data architecture ✅ Identify target markets ✅ Plan to iterate
41. Think about the downstream ✅ Common use cases ✅ Typical end users
42. Okay but how? ✅ Ask them ✅ Quarterly surveys ✅ Structured interviews
43. Okay but how? (contʼd) ✅ Dog food ✅ Sample applications ✅ SDKs / Client libraries ✅ Use tools & OpenAPI
44. Thank You! 🗂 Anthony Lusardi 🔗 liblab.com ✉ anthony@liblab.com 💬 linkedin.com/in/alusardi 🌲 linktr.ee/tony_codes 🔥 captivate.dev