Architectural decisions and their impact

There are quite a few talks out there explaining architectural patterns, but it is harder to find examples from actual projects and more specifically, making architectural changes in an existing project.

This talk aims to fill this gap by showing how two major architectural problems were identified, how the impacted the code and finally what we changed and how it improved the code. Since we use an open source project for this, you can even follow along by checking out the old versions, looking at the pull requests and obviously the current state for the result.

Transcript

1. Architektur- entscheidungen und ihre Folgen The Good The Bad The Ugly
2. Denis Brumann Solutions Architect Current Maintainer of Deptrac denis.brumann@qossmic.com @dbrumann
3. Command Line API Web App What kind of application is Deptrac?
4. Command Line API Web App What kind of application is Deptrac?
5. Command Line API Web App Interactive Non-Interactive What kind of application is Deptrac?
9. Web apps and APIs https://my-app.com/ MyApp DB MyApp
10. https://foo.my-app.com/ Interactive runtime in web apps and APIs https://acme.my-app.com/ ACME DB Foo DB MyApp
11. https://foo.my-app.com/ Interactive runtime in web apps and APIs https://acme.my-app.com/ ACME DB Foo DB MyApp Tenant-Aware Multi-Portal
12. Warning Signs Services creating other services (usage of new in code) Service Locator or factory-usage Config-objects (or arrays) being passed through
16. Possible Problems Runtime errors (invalid context, misconfigured services) Debugging is more difficult (which service/config was used?) More coupling & complexity
18. Lesson Avoid creating/configuring services at runtime
27. nikic/php-parser is only used here
28. nikic/php-parser is only used here Deptrac’s own structure
32. No longer contains dependency-references
35. Possible Benefits Switching dependencies is easier Refactoring is more contained Easier extraction
39. Possible Problems Mapping between objects can become annoying More code/duplication “Wrong” layers add complexity
40. Lesson Isolating layers helps contain changes and makes switching out parts easier