CodeFest 2019. Dylan Beattie (Skills Matter) — Architecture: «The Stuff That’s Hard to Change»

We’ve all heard of the idea of ‘software architecture’. We’ve read books about domain-driven design and event sourcing, we’ve been to conferences and learned about micro services and REST APIs. Some of us remember working with n-tiers and stored procedures... some of us are still using them. But the role of a systems architect is still one of the most misunderstood things about the software development process. What does the architect actually do? If you’re working with a systems architect, what can you expect from them? And if you are a systems architect, what are your team expecting from you? In this talk, Dylan will share his own insights into the idea of architecture as part of a software development process. We’ll explore some popular architectural patterns and processes — and a couple of obscure ones as well — and look at how, and when, you can incorporate those patterns into your own projects. We’ll talk about how the idea of software architecture has changed over time, and share some tips and advice for developers who find themselves working with architecture as part of their role.

Transcript

1. “The Stuff That’s Hard To Change” Dylan Beattie @dylanbeattie
2. From: The Boss To: Dylan Subject: Change of job role Dear Dylan, This is to confirm your change of job role to Systems Architect, effective immediately. You are now responsible for architecture, architecting, doing architect stuff, systems architecture, and architecting systems. Congratulations on your new role! Kind regards, Your Boss Change of Job Role
3. ARCHITECT LAUNCH PIPELINE BUS PYTHON CRASH MOUSE
4. https://www.theatlantic.com/technology/archive/2015/11/programmers-should-not-call-themselves-engineers/414271/
5. https://commons.wikimedia.org/wiki/File:Margaret_Hamilton_1989.jpg
7. https://franklloydwright.org/site/fallingwater/
8. https://www.dailytarheel.com/article/2016/03/founding-uncs-computer-science-department-was-an-experiment-but-it-paid-off-for-fred-
9. https://www.dailytarheel.com/article/2016/03/founding-uncs-computer-science-department-was-an-experiment-but-it-paid-off-for-fred- “Computer architecture, like other architecture, is the art of determining the needs of the user of a structure and then designing to meet those needs as effectively as possible within economic and technological constraints.” - Fred Brooks: "Planning a Computer System: Project Stretch”, 1962.
10. https://www.pcworld.com/article/258989/the_ibm_ps_2_25_years_of_pc_history.html
11. https://winworldpc.com/product/microsoft-visual-bas/10
12. https://www.arnnet.com.au/slideshow/557401/pictures-visual-history-netscape-navigator/
14. What is software architecture?
15. https://www.dailytarheel.com/article/2016/03/founding-uncs-computer-science-department-was-an-experiment-but-it-paid-off-for-fred- “Computer architecture, like other architecture, is the art of determining the needs of the user of a structure and then designing to meet those needs as effectively as possible within economic and technological constraints.” - Fred Brooks: "Planning a Computer System: Project Stretch”, 1962.
16. https://www.dailytarheel.com/article/2016/03/founding-uncs-computer-science-department-was-an-experiment-but-it-paid-off-for-fred- “Computer architecture, like other architecture, is the art of determining the needs of the user of a structure and then designing to meet those needs as effectively as possible within economic and technological constraints.” - Fred Brooks: "Planning a Computer System: Project Stretch”, 1962.
17. https://www.dailytarheel.com/article/2016/03/founding-uncs-computer-science-department-was-an-experiment-but-it-paid-off-for-fred- “Computer architecture, like other architecture, is the art of determining the needs of the user of a structure and then designing to meet those needs as effectively as possible within economic and technological constraints.” - Fred Brooks: "Planning a Computer System: Project Stretch”, 1962.
18. https://www.dailytarheel.com/article/2016/03/founding-uncs-computer-science-department-was-an-experiment-but-it-paid-off-for-fred- “Computer architecture, like other architecture, is the art of determining the needs of the user of a structure and then designing to meet those needs as effectively as possible within economic and technological constraints.” - Fred Brooks: "Planning a Computer System: Project Stretch”, 1962.
19. https://www.dailytarheel.com/article/2016/03/founding-uncs-computer-science-department-was-an-experiment-but-it-paid-off-for-fred- “Computer architecture, like other architecture, is the art of determining the needs of the user of a structure and then designing to meet those needs as effectively as possible within economic and technological constraints.” - Fred Brooks: "Planning a Computer System: Project Stretch”, 1962.
20. ? ? ?
25. Rene Descartes
26. Manifesto for Agile Software Development We are uncovering better ways of developing software by doing it and helping others do it. Through this work we have come to value: […] Responding to change over following a plan That is, while there is value in the items on the right, we value the items on the left more.
27. Principles behind the Agile Manifesto We follow these principles: [...] The best architectures, requirements, and designs emerge from self-organizing teams.
29. [Slide: the iPhone 1]
30. NewShiny.js!
31. https://www.dailytarheel.com/article/2016/03/founding-uncs-computer-science-department-was-an-experiment-but-it-paid-off-for-fred- ARCHITECTURE: 1. determine user needs 2. meet those needs 3. within economic and technological constraints.”
32. SOFTWARE ARCHITECTURE IN THREE EASY STEPS
33. Make Decisions Communicate Decisions Reinforce Decisions
34. HOW TO MAKE DECISIONS https://www.flickr.com/photos/leviathana/88146176
35. 1. What Have You Got? Understand your Existing Technology
36. Vasyatka1 / CC BY-SA 4.0 / https://commons.wikimedia.org/wiki/File:Munich_Airport_T1_L4_passport_controls.jpg
37. WEBSITE THE INTERNET HTTP
38. “I don’t care about what anything was DESIGNED to do – I care about what it CAN do.” Gene Kranz, NASA Mission Director, Apollo 13
40. 2. What Do You Need? Asking the Right Questions
43. 3. What Can You Build? Understand your Capabilities
44. davetoaster / CC BY 2.0 / https://www.flickr.com/photos/dfoster/3722602616/
49. 4. What Can You Buy? Look for platform-as-a-service and software-as-a-service solutions
50. JD Lasica / CC BY 2.0 / https://www.flickr.com/photos/jdlasica/8535984776 There are some things money can’t buy. For everything else, there’s MasterCard.
51. 5. What Can You Lose? Look for Redundancies and Duplication
52. Whatleydude / CC BY 2.0 / https://www.flickr.com/photos/whatleydude/3862398238
53. DECIDE WHAT TO DO (The easy part)
54. COMMUNICATING DECISIONS
55. DESIGN YOUR SOLUTION https://theconcourse.deadspin.com/a-brain-meme-in-the-wild-1795721849
56. https://funnyjunk.com/Ikea+instructions/funny-pictures/5557042/
57. The Problem With Diagrams
63. Mercutio Norman Mandrill Excelsior \\JK6GB87\M$
64. Mercutio Norman Mandrill Excelsior \\JK6GB87\M$ Key to Yourdon/DeMarco notation Database or Filesystem Function Data Flow Input / Output
65. “Mercutio” (.NET service that populates email templates) “Norman” (.NET app that sends emails) “Mandrill” (Mailchimp SMTP relay service) “Excelsior” (SQL Server database of customer details) \\JK6GB87\M$ (Windows file share with Marketing email templates) Key to Yourdon/DeMarco notation Database or Filesystem Function Data Flow Input / Output
66. Key to Yourdon/DeMarco notation Database or Filesystem Function Data Flow Input / Output
67. “Mandrill” (Mailchimp SMTP relay service) “Excelsior” (SQL Server database of customer details) Key SQL Database Windows Service SMTP email relay ADO.NET records “Mercutio” (.NET service that populates email templates) “Norman” (.NET app that sends emails) \\JK6GB87\M$ (Windows file share with Marketing email templates) Network fileshare SMB File share RabbitMQ SMTP
68. “Mandrill” (Mailchimp SMTP relay service) “Excelsior” (SQL Server database of customer details) Key SQL Database Windows Service SMTP email relay ADO.NET records “Mercutio” (.NET service that populates email templates) “Norman” (.NET app that sends emails) \\JK6GB87\M$ (Windows file share with Marketing email templates) Network fileshare SMB File share RabbitMQ SMTP .txt & .html files. (Windows authentication required.) ADO.NET Windows authentication via Mercutio service account RabbitMQ (SAAS hosted on CloudAMQP) SMTP Port 993 TLS enabled
73. Mercutio (Core Logic) EntityFramework Data Adapter “Excelsior” (Customer Database) ICustomerDataPort ITemplatePort FileSystem Template Adapter Windows File Share IMailSender RabbitMQ Mail Adapter (implementation) Mercutio Entity Framework Data Provider “Excelsior” (Customer Database) Windows File Share RabbitMQ Mandrill (SMTP relay component)
74. REINFORCING DECISIONS
75. VALIDATION (are we building the right thing?) VERIFICATION (are we building the thing right?)
80. [restroom, pissoir]
84. I’VE REVIEWED YOUR C# CODE AND I STILL DON’T KNOW WHAT IT DOES. Dude. My team is using Scala.
85. public class CustomerRepo { public CustomerRepo(IdentityMap<Customer> map) { this.map = map; } public Customer GetCustomer(int customerId) { return map.FindById(customerId); } }
90. API SERVER API CLIENT {fake JSON} {spec tests}
91. API SERVER API CLIENT {fake JSON} {spec tests}
94. https://xkcd.com/844/
95. Dylan Beattie @dylanbeattie dylan@dylanbeattie.net