Different programming models develop different mental models

An expansion on "How to authenticate a user without a username, password or database", I share how learning different programming models and paradigms has helped me solve problems more effectively in my main programming language – in this case, learning the unique programming model of Erlang. With a fun demo to boot.

Presentation at Abstractions II (abstractions.io) in September 2019, in Pittsburgh, USA.

Transcript

1. How to authenticate a user without a username, password or database
2. Different programming models Develop Different mental models
3. Mental models allow you to see problems through a different filter / angle / perspective
4. “A change of perspective is worth 80 IQ points.” – Alan Kay
5. “A developers main responsibility is to defend and maintain the conceptual integrity of the codebase.” – Aslam Khan
6. Different programming models Develop Different mental models
7. Ricardo García Vega @bigardone Joe Armstrong @joeerl Sarah Drasner @sarah_edo
8. This is serious business a little fun
9. this app does nothing .com “This app literally does nothing.” TechCrunch
10. Open your mind
11. i. Identity claim ii. Identity verification iii. Identity storage How does authentication work?
12. Let’s play… How to authenticate a user!
13. Claim Verify Store How would you do identity claim? a. Don’t be silly, just use OAuth b. Gait analysis c. Use their face d. Security is a lie
14. Claim Verify Store How would you do identity claim? a. Don’t be silly, just use OAuth b. Gait analysis c. Use their face d. Security is a lie
15. Claim Verify Store How would you do identity verification? a. Obviously a blood test b. OAuth, you will be assimilated c. Send them an OTP d. Fingerprint or retinal scan
16. Claim Verify Store How would you do identity verification? a. Obviously a blood test b. OAuth, you will be assimilated c. Send them an OTP d. Fingerprint or retinal scan
17. Claim Verify Store How would you do identity storage? a. Throw it in a file - that’s not a database is it? b. Mechanical turk: an army of humans write it out on paper c. Machine learning serverless blockchain™ d. Keep it in memory and never let the server die
18. Claim Verify Store How would you do identity storage? a. Throw it in a file - that’s not a database is it? b. Mechanical turk: an army of humans write it out on paper c. Machine learning serverless blockchain™ d. Keep it in memory and never let the server die
19. How does nada work?
20. Claim Verify Store Facial recognition One time pin Memory storage Slack’s “magic links” or an OTP sent to an email address Erlang process storing face to email mapping in memory Face to email mapping used to identify a user
21. Nada Faces API Nada App AWS Rekognition Sign up AWS S3 { selfie } { face_id } { email selfie } Claim { email face_id } Store { otp } Verify
22. Nada Faces API Nada App AWS Rekognition Log in AWS S3 { selfie } { face_id } { email face_id } Store { otp } Verify { selfie } Claim
23. Claim Verify Store Face to email mapping used to identify a user Facial recognition # @ Face Face ID Email Image
24. Claim Verify Store One time pin Slack’s “magic links” or an OTP sent to an email address user@example.com Log in
25. Claim Verify Store One time pin Slack’s “magic links” or an OTP sent to an email address user@example.com mail@nada.com thisappdoesnothing.com/djtufy TO FROM
26. Claim Verify Store One time pin Slack’s “magic links” or an OTP sent to an email address SUCCESS!
27. Claim Verify Store Memory storage Erlang process storing face to email mapping in memory Erlang VM Web server process Agent process ...
28. Claim Verify Store Memory storage Erlang process storing face to email mapping in memory Erlang VM Web server process “a7j3hgdg”: “bob@gold.com” “jmd739sh”: “sam@mail.com”
29. Demo
31. Erlang process as a database
32. Java Fault-tolerance Erlang “Write once, run anywhere.” “Write once, run forever.”
33. Clojure Java VM Elixir Erlang VM “BEAM”
34. 2019 Today 1986 33 years
 ago 2011 ~8 years ago 24 years ago 1995 12 years ago 2007
35. Object-oriented Functional Functional Programming Paradigms Ruby JavaScript Elixir
36. Programming Models “Everything is an object” “Everything is a function” “Everything is a process” Ruby JavaScript Elixir
37. Before FP
38. After FP
39. “[Erlang] is the language of the system.” Rich Hickey
40. Program System Single process Multiple-processes make up a whole
41. TaxCalculator TaxReport “calculate_net_income”
 gross_income: 80000 net_income 56000
42. Process E Process D Process C Data store process Process A
43. Erlang data stores • Mnesia • ETS (Erlang Term Storage) • Process state (GenServer/Agent) • *Riak
44. • Are there relationships between the data you store? • Are you storing time-related data? • Do you need to be able to look at the database in the past? How do you intend to query the data?
45. • Data + relationships • Relationships between data (graph) • Simple store-retrieve • Mapping (Key-Value) • Data stored over time • Changes as facts stored over time (immutable database) Typical data storage options by query
47. What have we learned?
48. Different programming models Develop Different mental models
49. Have fun
50. You can do “AI”
51. A new programming model
52. Choose a database
53. Don’t cargo-cult software design
54. Make a responsible decision
56. Fora Health is a product of Ctrl Group
57. Cognition Kit is a joint venture between Ctrl Group and Cambridge Cognition.
58. learn.ctrl-group.com
59. thank you Simon van Dyk @siefi