Vertical Slice Architecture Myths You Need To Know! — Transcript

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1. 0:00hey everybody it's Derek Martin from cod
2. 0:01opinion.com as with anything in our
3. 0:04industry that gains some traction by the
4. 0:05waterer Community it develops some
5. 0:08misconceptions vertical slice
6. 0:09architecture Falls exactly into this
7. 0:11trap but don't worry I'm going to
8. 0:13demystify some of these misconceptions
9. 0:16why they exist and set the record
10. 0:18straight easily the number one
11. 0:19misconception not even close this is a
12. 0:22question comment or confusion is this
13. 0:25idea of share nothing or that how do you
14. 0:27share between slices or between features
15. 0:30I think the reason why there's this
16. 0:31misconception or confusion to how this
17. 0:32works is because people want features to
18. 0:34be completely independent when that's
19. 0:36not really the case often times there's
20. 0:39relation between the two that could be
21. 0:40workflow or that could be just commands
22. 0:43or queries and a subset of them that's
23. 0:45actually what the feature is and this is
24. 0:46actually pretty common I'll give you
25. 0:48some examples of this but before I do
26. 0:50I'd like to thank Avent store for
27. 0:51sponsoring this video event store DB is
28. 0:53a new category of operational database
29. 0:55built for event sourcing cqrs and event
30. 0:58driven microservices from for more on
31. 1:00event store DB check out the link in the
32. 1:02description the most common example of
33. 1:03this is your underlying domain or data
34. 1:05model this thing is shared across
35. 1:08features sure your features are given
36. 1:10use cases specific use cases but they
37. 1:12may all be sharing that same underlying
38. 1:14domain or data model the key aspect of
39. 1:16this is you don't have that domain model
40. 1:18or data model that's shared between the
41. 1:20entire system no it's very specific it's
42. 1:23vertical and what those features that
43. 1:25actually needed that should be very
44. 1:27narrow very focused another way of
45. 1:29thinking about this is let's say we had
46. 1:31some validation between features but
47. 1:33there's specific validation that we need
48. 1:34to do in two specific features pretty
49. 1:37much the same way well just create
50. 1:40something that's shared between the two
51. 1:41features that's fine how do you do that
52. 1:44just use the same class whatever it is
53. 1:46that you're sharing that you're going to
54. 1:48have within those two features there's
55. 1:49nothing wrong with this not each new
56. 1:51feature needs to be completely
57. 1:53independent in what it's using it's just
58. 1:55narrowing that focus a different way of
59. 1:57looking at it is let's say these two
60. 1:59featur features they're using one
61. 2:01particular way to validate and then the
62. 2:03other three features maybe they have
63. 2:04something completely different that's
64. 2:05kind of the benefit of having things by
65. 2:07feature by verticals is that you can
66. 2:09decide what that implementation looks
67. 2:11like maybe something shared between a
68. 2:13couple or a few of them maybe they're
69. 2:15not and this relates to what I think is
70. 2:16probably the second most common
71. 2:18misconception which there's little or no
72. 2:20abstraction so this misconception I
73. 2:22think exists because people are
74. 2:24generally thinking about layers and if
75. 2:25they're thinking about vertical slices
76. 2:27what happens to the layers well the it
77. 2:29can still be there nobody's saying not
78. 2:31to use layers nobody's not saying to not
79. 2:33use abstractions so for example if you
80. 2:36had some type of data access layer or
81. 2:38whatever that was that's not just saying
82. 2:40that if you have some type of vertical
83. 2:41slice or feature that you don't have
84. 2:43that abstraction of data access you can
85. 2:46where I think this gets a little bit
86. 2:48confusing is because now you're deciding
87. 2:51specifically in a given vertical slice
88. 2:53or feature how you want to do that data
89. 2:55access a lot of this now comes down to
90. 2:57coupling is the question is do you need
91. 3:00the abstraction maybe you do maybe you
92. 3:02don't but the idea that you don't have
93. 3:04to use one or that you shouldn't or that
94. 3:06there's no layers is a misconception
95. 3:08here's an example let's say you're using
96. 3:10an orm for your data access and all
97. 3:13these vertical slices these features
98. 3:15let's say there's a dozen of them that
99. 3:16actually depend on this omm or an
100. 3:18instance of the orm do you need the
101. 3:20abstraction maybe you do maybe you don't
102. 3:23if you needed to change that underlying
103. 3:25uh database or orm or whatever you want
104. 3:26it to do how much work is it to actually
105. 3:29change those dozen places this is very
106. 3:31different if you have uh some type of
107. 3:33data access layer that's coupled
108. 3:36hundreds of times so the the focus
109. 3:38becomes more narrow and that's what
110. 3:40people then start thinking about well do
111. 3:42I need the abstraction or can I just
112. 3:43change it when I need it if it's
113. 3:45testable and you don't need to create
114. 3:47your own type or one abstraction around
115. 3:49it maybe you don't but that's not to say
116. 3:51that there's little to no abstraction
117. 3:53it's really up to you and this leads us
118. 3:55to another misconception which is
119. 3:56there's a low barrier to entry meaning
120. 3:59that if you want to get into vertical
121. 4:00slice architecture it's a lot easier
122. 4:02than say clean architecture I disagree
123. 4:04with this because I think fundamentally
124. 4:07it's not about clean architecture or
125. 4:09vertical slice architecture or aventurin
126. 4:12architecture all these different types
127. 4:13of architectures you ultimately use that
128. 4:15make your architecture fundamentally
129. 4:17it's understanding what the problems are
130. 4:20why you're applying certain patterns or
131. 4:21certain Concepts and often times this
132. 4:24relates to tradeoffs around coupling and
133. 4:27cohesion that's really what you're
134. 4:29battling
135. 4:30most of the time and there's just
136. 4:31different ways of doing it so I don't
137. 4:33think there's a lower barrier to entry
138. 4:34with vertical slice architecture I think
139. 4:36maybe on the surface it seems that way
140. 4:39but you can screw up anything that you
141. 4:40don't really understand now another
142. 4:42misconception and I kind of alluded to
143. 4:44this a little bit earlier is that
144. 4:45features don't impact other features the
145. 4:48reason why this misconception exists is
146. 4:49because this idea incorrectly that there
147. 4:51share nothing that each feature is going
148. 4:53to be or vertical is going to be
149. 4:55completely independent it's just not the
150. 4:57case you're going to have some coupling
151. 4:59between between features often times
152. 5:01this could be business processes or
153. 5:02workflows where one thing kind of kicks
154. 5:04off a business process and then it hands
155. 5:06it off to another feature you're going
156. 5:08to have coupling there how you couple is
157. 5:10a different story and I'll get to that
158. 5:12in a second but the idea that you're not
159. 5:14going to have one feature affect another
160. 5:16feature is not really the case so why is
161. 5:20that important because you're less
162. 5:23likely to have features impact other
163. 5:25features because you're not going to
164. 5:26have some massive layer that's coupled
165. 5:29to every feature that's the whole point
166. 5:31of vertical slices and focusing on kind
167. 5:33of the utility of each one and how you
168. 5:35want to implement that rather than
169. 5:38having your entire system depend on one
170. 5:40data access um layer or whatever the
171. 5:43case may be you're splitting things up
172. 5:45so again you're controlling coupling so
173. 5:48that's why kind of this notion of
174. 5:50features won't affect other features
175. 5:51it's not that they won't it's that you
176. 5:53won't have one feature that's specific
177. 5:55to one specific use case it won't likely
178. 5:57affect another feature that's completely
179. 6:00unrelated but you absolutely can have
180. 6:02one feature affect another feature
181. 6:04that's directly related and lastly to
182. 6:06piggyback up the last one is it requires
183. 6:08messaging to decouple Features so
184. 6:10something like Pub sub and topics or
185. 6:13messaging in cues and this misconception
186. 6:15is often because that's how it's
187. 6:16actually implemented or given in
188. 6:18examples or you see videos like me
189. 6:20explaining event Riven architecture Pub
190. 6:22sub or using some type of orchestration
191. 6:25to work on business processes and
192. 6:26workflows so when you have something in
193. 6:28one feature happen
194. 6:30you publish an event and some other
195. 6:31feature can pick that up and continue on
196. 6:33the workflow kind of like what I was
197. 6:35mentioning earlier but that's not
198. 6:36necessarily how things have to be
199. 6:38implemented asynchronous messaging is
200. 6:40just a way to remove the temporal
201. 6:42coupling you're going to have some form
202. 6:43of coupling some degree of coupling
203. 6:45messaging is just one way of handling it
204. 6:47but by no means is messaging required in
205. 6:49a vertical slice architecture now the
206. 6:51last thing to touch on isn't a
207. 6:52misconception at all I think it's
208. 6:54actually kind of the reverse which that
209. 6:56there's not enough emphasis on when you
210. 6:58might want to consider a vertical slice
211. 7:00architecture which is really you want to
212. 7:02focus on use cases it isn't to me very
213. 7:06applicable or something you should be
214. 7:07striving for if all you're developing is
215. 7:10crud and that's because your use cases
216. 7:12are your features your features are your
217. 7:14vertical slices the idea that you have
218. 7:16some type of capabilities your system
219. 7:18provides some type of behaviors the
220. 7:21behaviors are what you're focusing on
221. 7:23that's the idea of organizing your code
222. 7:25around these use cases around these
223. 7:27features around these behaviors these
224. 7:29capabilities what does your system do if
225. 7:32it's just create read update delete and
226. 7:35that's how you're going to organize your
227. 7:36code sure I guess but a lot of the value
228. 7:39here is that your code is expressive
229. 7:41about what it actually does so hopefully
230. 7:44I cleared the air a little bit on some
231. 7:46of the misconceptions that you might
232. 7:47have read or watched in videos I hope
233. 7:49this gives a better illustration about
234. 7:51what vertical SS architecture is and
235. 7:53isn't if you enjoyed videos like this
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