Pain Driven Development

1. Pain-driven development
Alexandr Sugak,
.NET developer/architect at Sigma Software,
Kharkiv F# User Group

2. About me
 32 years old;
 Programming for ~12 years;
 Did mostly .NET;
 Worked on Web and Desktop apps, DBs, Web/Win Services, IDE plug-ins,
SPAs, mobile apps, integrations;

3. About me
 32 years old;
 Programming for ~12 years;
 Did mostly .NET;
 Worked on Web and Desktop apps, DBs, Web/Win Services, IDE plug-ins,
SPAs, mobile apps, integrations;
 Never liked it.

4. Agenda
 Pain #1 -> example(s) -> Guiding principle #1;
 Pain #2 -> example(s) -> Guiding principle #2;
 Pain #3 -> example(s) -> Guiding principle #3;
 Pain #4 -> example(s) -> Guiding principle #4.

5. How we do .NET today
Platform:
 Windows;
 IIS;
 MS SQL Server;
 Azure.
Technology:
 C#;
 ASP.NET
MVC/API;
 Entity Framework;
 WCF
 Angular.JS.
Tools:
 Visual Studio;
 R#;
 NuGet.exe;
 TFS;
 TeamCity.
Libraries:
 AutoMapper;
 Json.NET;
 Log4Net;
 Rhino Mocks.
Architecture:
 3-Tier;
 DDD “Light”;
 SOA;
 Microservices.

6. But now we have .NET Core and a new
open-source MSFT, right?

7. But now we have .NET Core and a new
open-source MSFT, right?
https://github.com/NuGet/NuGetGallery/pull/4437
Wrong

8. .NET Core + Linux =
 C#;
 ASP.NET Core;
 EF Core;
 SQL Server for Linux;
 Visual Studio for Mac;
 <something> Core;

9. DISCLAIMER
 Subjective matter!
 You will have your project’s requirements;
 Not every project is a “green field” project;
 This is not about “all new shiny things are better”.

10. Pain of using “magic” frameworks
 You install NHibernate;
 Everything works as expected;
 You create your first entity – so far so good;
 You create second entity – it doesn’t work;
 You spend 3 hours to understand that the problem is that your new entity
has “Date” property and it is not escaped in generated T-SQL.

11. Principle 1: direct SQL queries (Dapper)

12. Principle 1: direct SQL queries (F# +
ADO.NET)

13. Principle 1: direct SQL queries (Go)
https://github.com/jmoiron/sqlx

14. Principle 1: Request -> Response
https://suave.io

15. Principle 1: Request -> Response
https://golang.org/pkg/net/http/

16. Principle 1: “less magic”
 Avoid accidental complexity at all cost;
 Magic things: ORMs, AOP, overuse of conventions, code generation,
reflection etc.;
 Willing to trade some effort for the full control over solution.

17. The “it works on my machine” pain
 You do the change and test it locally – it works;
 You push your changes to repository;
 CI build fails with “Cannot load an assembly”;
 You spend next 3 hours trying to understand why.

18. Principle 2: predictable builds

19. Principle 2: locking dependencies
Package Manager Platform Has lock file?
Paket .Net
Nuget.exe .Net
Npm JS
Yarn JS
dep Go

20. Principle 2: configuring IIS
http://tavalik.ru/ustanovka-wordpress-na-iis/

21. Principle 2: configuring nginx

22. Principle 2: predictable state
 Reproducible builds: “single script to rule them all”;
 Transient dependencies, lock files;
 Immutable servers/infrastructure;
 Configuration-driven environment.

23. The “edit, compile, wait, repeat” pain
 You do the change to the model/view/controller;
 You compile your 35 projects solution - 30 sec;
 You reload your browser and wait for:
 IIS to reload the app – 5 sec;
 Your app to initialize – 15 sec;
 The page to load – 2 sec;
 You manually restore the page state – 5 sec;

24. The “edit, compile, wait, repeat” pain
 You do the change to the model/view/controller;
 You compile your 35 projects solution - 30 sec;
 You reload your browser and wait for:
 IIS to reload the app – 5 sec;
 Your app to initialize – 15 sec;
 The page to load – 2 sec;
 You manually restore the page state – 5 sec;
 And it did not work;
 Repeat.

25. The “edit, compile, wait, repeat” pain
https://faculty.washington.edu/ajko/books/cooperative-software-development/history.html

26. Principle 3: File watchers

27. Principle 3: React hot loader

28. Principle 3: next level
 Not just time travel, I want to observe changes across time at one glance;
 Not just hot reload, I want to see changes for all states, on all pages;
 Visual programming?
 Programming by example?
 See Bret Victor’s work, e.g.
http://worrydream.com/#!2/LadderOfAbstraction

29. Principle 3: build feedback
 Run entire test suite on every commit;
 Run all linters on every commit;
 Deploy 10 version of the app per day;
 Receive notifications on every failure: Slack integration for CI builds and in-
app critical errors;

30. Principle 3: shorten feedback loop
 As a programmer, I want to see the effect of the changes I do
immediately so that I could be more efficient;

31. The “your skills are now obsolete” pain
 You start as a .NET programmer in 200X;
 You learn ASP.NET Web Forms: the event model, the View State, the Ajax
Toolkit, etc.;

32. The “your skills are now obsolete” pain
 You start as a .NET programmer in 200X;
 You learn ASP.NET Web Forms: the event model, the View State, the Ajax
Toolkit, etc.;
 Time passes, you are in the 201X;
 You now have a part of your brain that is forever lost.
How to disable
ViewState
https://commons.wikimedia.org/wiki/File:Brodmann_area_45_lateral.jpg

33. The “your skills are now obsolete” pain
 You start doing SPAs in the 201X;
 You learn AngularJS: the template language, the directives, the custom
HTTP client, etc.;

34. The “your skills are now obsolete” pain
 You start doing SPAs in the 201X;
 You learn AngularJS: the template language, the directives, the custom
HTTP client, etc.;
 …
 See the pattern?

35. Principle 4: things I cannot reuse
 WebForms;
 WinForms;
 SharePoint;
 Visual Studio + R#;
 AngularJS http client;
 “Click to deploy to Azure”;
 and many more.

36. Principle 4: things I can reuse
 JavaScript;
 Object Oriented/Functional programming, SOLID;
 Event-driven/reactive systems;
 Web, http, networks;
 SQL;
 Emacs/Vim;
 Actor Model;
 Stream Processing;
 Machine Learning;
 Statistics;
 UX;
 And many more.

37. Principle 4: Reactive Extensions
http://reactivex.io/

38. Principle 4: composition and reuse
 As a programmer, I want to be able to reuse the skills and knowledge I
have when working on a new project so that I could be more efficient and
be in demand on job market;

39. Summary
 Business value first, technical wizardry second;
 Automate all the things!
 Do not make compromises with technology, ask for more!
 Learn how to build systems, not how to use frameworks.

40. What are your Principles?

41. https://www.facebook.com/groups/kharkivfsharp/

42. Thank you!