Shadowing Practice: Your API Can’t Handle Real-World Integrations - Learn English Speaking with Video

Let's say you build a nice REST API product, but then you release it and you find out your customers can't integrate it with their own systems.

One customer needs a CRM ID, another needs a warehouse reference,

and someone asks whether you can just add one more field for some external system that they use.

And before you know it, your schema becomes a huge mess.

Now, in this video I'll show you a much cleaner approach that won't require you turning your API into a junk drawer.

It's very simple to build, the Stripe API does it this way, and I think more APIs should add this feature because it makes them way more usable.

Now, what I've learned over the years is that with ideas like this, it's not just important that you know they exist, but that you also understand the design trade-offs behind them.

And that's exactly what I go deep into in Software Design Mastery.

This is not just another course with patterns and principles, it's a comprehensive system for thinking about design and trade-offs.

If you want to be part of that, join the waiting list at iron.codes.mastery.

The link is in the description.

Now, I'm starting with a simple working FastAPI app.

So this is the main file.

I'm using a SQL Alchemy database for this FastAPI app.

And it's very basic.

It just has a few concepts.

So there is a customer, there is a product, and there are orders.

And this is what the API allows us to work with.

And as you can see, I have a declarative base, just like you're supposed to do with SQLAlchemy.

And then I create these different classes.

So customer has ID, email, name, there are orders, there are products, there are also mapped to orders.

And an order itself is, again, linked to a customer and a product and has some other data as well.

This is a pretty basic setup.

And by the way, the full code example, as usual, you can find in the code example, Git repository.

The link is also in the description of the video.

Now next to these models there is a couple of other modules as well, like the routes, which is the most important one,

where we have different endpoints like posting to the customer's endpoint to create a new customer.

There is an endpoint for getting the customer by ID.

You can patch a customer.

You can do the same thing for products and the same thing for orders as well.

So let's start this API using UVcorn.

And now I can send a simple request to create a new customer.

Like so.

Now we have this customer with ID 1.0.

And then I can use the API in different ways.

For example, here I'm retrieving that same customer from the database that I just created.

Now, once this app starts integrating with other systems, then new requirements are going to appear very quickly.

Maybe one of your clients has a CRM

and they want their own customer ID that they store along with the customers in your API.

Or some accounting system wants a contact reference.

or a warehouse tool wants an order reference, a migration script wants to remember some old legacy identifier.

And these fields are really important, but they're not really part of the core domain model of your API.

You can't know in advance what all these fields are going to be

because they're going to be dependent on the clients that use your API.

These are really integration specific.

Now, some APIs offer custom fields for this

and then it's often implemented like you need to specify what custom fields there are.

These things get their own ID and then you can read

or write these custom fields that are then attached to different resources in your API.

But there is actually a simpler way to do it and that's by using a really great data structure called JSON.

The idea is, and this is also how Stripe sort of does it is

that you have a metadata or custom data field

that is a JSON format that your customer can basically set in any way that they want.

But you don't just want to add a JSON field

and leave it at that because then it's not really usable

because if you want to update let's say one value in

that JSON structure you need to pass in the complete JSON

data into the request in order not to delete everything that's in there.

So we need to implement it in a specific way

and that's also how it's done in stripe

and you can actually add this to your api as well

so we want let's call it custom data to behave like

a normal field in the api clients should be able to

send it on create request they should be able to update it

and pass request and it should also be able to remove individual keys without replacing the whole object

so they should be able to send a key value pair to add

or update the value they should be able to send a key with a null value

which will unset it

and they should also be able to send an empty object to basically clear all of the custom data

and combine this gives you a very flexible and predictable behavior

that works very well for apis

so how do we add this here well there's a very logical place in the database models actually

which is that we have this declarative base

because obviously we want this custom data to be available for all of the different resources for customers for products

and for orders and we want to avoid

that we copy this all over the place

so what you can do here is actually rely on inheritance

even though i'm personally more of a fan of composition in this case i think inheritance is a good solution

because it's already built into sql alchemy

so what we'll do is we will add this custom data field to the declarative base

so when you do that this is actually what that looks like

so base now has a custom data field it's a json type we won't allow it to be null

because we always want it to be an object

so that's what we have

but now the only thing we need to do is of

course define the behavior of changing this custom data object now you could add

that to the routes but again you'd have to copy paste

that behavior all over the place and actually there is a very easy way to add it to declarative base in SQLAlchemy.

The first thing that you can do is define a function that applies the data to the custom data.

So and then we'll call this from somewhere else.

So this gets a dictionary with the new data and there we basically have to work with the three different cases.

The first case is very simple that if the patch is the empty dictionary then

self.customData is simply going to be the empty dictionary and we're done.

We can return.

So this is basically a way of clearing the custom data.

The next step is that we can go through the key value pairs in the patch and apply them one by one.

So first let's store the custom data in a temporary variable.

And if that doesn't happen to exist, let's make it the empty object.

So we don't run into any issues we always note that there is an object.

100

So for key, the value in the items of patch,

101

and then now we can handle the two remaining values.

102

So if the value is none, that means that we want to unset the key.

103

So we do current.pop the key.

104

And default, if the key doesn't exist, we simply ignore it.

105

Else, that means the key has a value.

106

So in that case, current key equals the value.

107

So we simply set the value.

108

And then finally, once we've done this, we set the custom data to the current object,

109

so that this is also handled correctly if this is the empty dictionary.

110

Now maybe you could do this directly on the custom data, but I kind of like using a temporary variable here feels a bit safer.

111

But now the magic is that we can have a method apply patch and this gets data.

112

And this actually overrides a standard method in the declarative base.

113

So this is going to be called automatically whenever we update the object.

114

And here what we're going to do is we're going to loop over the items in data

115

and then we can simply handle the cases here.

116

So if the value is none and the key is not custom data we can simply ignore this case.

117

And if the key is custom data,

118

well in that case we're going to call our custom data patch method

119

and we're simply going to pass the data like

120

so else we can use setAther to set the key to the value

121

so this basically means the standard behavior of SQLAlchemy

122

and then the only thing left to do is

123

that in our schemas for creating and reading customers and

124

so on we have to make sure that there is a custom data field.

125

So here's how you could do that.

126

It's very simple.

127

We simply define custom data as part of our schema by simply adding it there to the classes.

128

So in this case I created a custom data schema

129

and then whenever I create a customer I make a subclass of

130

that so we can also set the custom data whenever we create the customer.

131

And I did the same thing for reading the customers

132

and you can also add it for other things like creating products for example.

133

So adding the custom data here is actually very little work.

134

So now that we have this, it's really easy to add custom data to our resources.

135

For example, here I'm creating a new customer where I set an actual customer ID in the CRM

136

that I pass as custom data and now my customer has this as part of the object. And

137

if I want to add more custom data I can actually

138

simply pass it by setting a key value pair in the custom data like so.

139

And as you can see it currently does something weird

140

which is that it puts custom data inside the custom data and that's because I made a mistake.

141

Namely when I apply the catch I shouldn't pass all the data here I should actually pass the value like so.

142

Let's try this again I've deleted the database

143

and I'm creating the customer one more time and now let's add another custom data field.

144

As you can see now it has the desired behavior

145

so now it sets our billing ID but it doesn't delete the CRM custom ID which is really neat.

146

We can also remove a custom field value by simply setting the value to null like so.

147

As you can see We get the customer back.

148

It keeps the CRM customer ID, but it has deleted billing ID.

149

And finally, if we want to clear all custom data, we simply set it to the empty object.

150

And that also works.

151

So overall, I think this is a really useful pattern you can add to your API.

152

And it's actually really simple to do, especially if you're using something like SQL Alchemy.

153

The only thing you need to do is basically add this piece of code to your declarative base.

154

And anything that inherits from this is going to have custom data with the behavior that I demonstrated in this video.

155

And of course, you need to make sure that custom data is part of your schemas, but that's like a pretty easy thing to add.

156

So in my opinion, more APIs should add this feature because this is really useful, but only use this for the right thing.

157

So good uses for this are external IDs that you want to couple with,

158

integration-specific references, small optional flags or tags, data that is useful context but not core domain structure.

159

I wouldn't use this to store important business logic or data

160

that you constantly need to query or search through things that really should be first-class fields in your API.

161

Now a good rule of thumb is that

162

if the field is part of the meaning of the model make it a real column.

163

If it's just custom context then it fits great into a custom data object like this.

164

And by the way

165

if you enjoy these types of practical design breakdowns where we go beyond just making something work

166

and look at why design is good

167

or bad like this video subscribe to the channel it helps

168

me out a lot in summary what makes this feature nice is

169

that it's not just storing JSON but that we slightly modify the behaviors

170

that it's really easy to use

171

and by making it part of the declarative base it's really

172

easy to add to the various resources in your API

173

but I'd like to see what you think have you added

174

this type of metadata custom data thing to your API's have

175

you seen other API's implement this feature let me know in

176

the comments I haven't talked much about how to actually organize

177

the business logic in this API like the database the routes

178

anything else your API needs watch this video next to learn more about how to properly design

179

and using a really cool pattern called ports and adapters.

180

Thanks for watching and see you next time.

📺 Mismo canal

DRY Often Makes Your Code Worse

Business EnglishUniversity StudentsWorking Adults

✨ Recomendar Video

338 oraciones

Vocabulario y notas de pronunciación para esta lección

Este vídeo tiene 180 frases y 2333 palabras para practicar shadowing. La parte hablada dura 12:59. El hablante habla rápido, unas 180 palabras por minuto, así que espera sonidos enlazados y reducidos. El 85 % de las palabras está entre las 3.000 más comunes del inglés; conviene repasar el resto antes de empezar.

Vocabulario clave de este vídeo

15 palabras del vídeo que vale la pena aprender, con su pronunciación y significado:

Palabra	Pronunciación	Significado
custom sustantivo	/ˈkʌstəm/	costumbre, usanza
patch sustantivo	/pæt͡ʃ/	parche, cureta
database sustantivo	/ˈdeɪtəˌbeɪs/	base de datos, banco de datos
resource sustantivo	/ɹɪˈzɔːs/	recurso
delete verbo	/dɪˈliːt/	deletear
dictionary sustantivo	/ˈdɪk.ʃəˌnɛ.ɹi/	diccionario, tumbaburros
define verbo	/dɪˈfaɪn/	determinar, definir
implement verbo	/ˈɪmpləmənt/	implementar
stripe sustantivo	/stɹaɪp/	franja, raya
ignore verbo	/ɪɡˈnɔː/	ignorar, desoír
temporary adjetivo	/ˈtɛmp(əˌɹ)ɛɹi/	temporario, temporáneo
domain sustantivo	/ˌdəʊˈmeɪ̯n/	dominio
integration sustantivo	/ˌɪn.tɪˈɡɹeɪ.ʃən/	integración
variable adjetivo	[ˈvæɹ.i.ə.bl̩]	variable
warehouse sustantivo	/ˈwɛə(ɹ)haʊs/	almacén, depósito

Phrasal verbs que vas a escuchar

Palabra	Significado
find out verbo	averiguar, anoticiarse
go through verbo	atravesar

Gramática en este vídeo

Las estructuras que más usa el hablante, con las palabras exactas del vídeo:

Estructura	En el vídeo
Present perfect have/has + participio pasado — una acción pasada que sigue importando ahora	I've learned · we've done · I've deleted
Voz pasiva be + participio pasado — importa lo que ocurre, no quién lo hace	are also mapped · is also handled · be called

Pronunciación a tener en cuenta

El hablante usa 35 contracciones y formas reducidas, como I'm, we're, doesn't. Dilas en su forma corta, tal como las oyes.

Los sonidos de “sh” y “zh”: dictionary /ˈdɪk.ʃəˌnɛ.ɹi/, integration /ˌɪn.tɪˈɡɹeɪ.ʃən/, composition /ˌkɑm.pəˈzɪʃ.ən/, migration /maɪˈɡɹeɪʃ(ə)n/, optional /ˈɑp.ʃə.nəl/
Palabras largas — cuida el acento: dictionary /ˈdɪk.ʃəˌnɛ.ɹi/, temporary /ˈtɛmp(əˌɹ)ɛɹi/, integration /ˌɪn.tɪˈɡɹeɪ.ʃən/, inheritance /ɪnˈhɛɹɪtəns/, comprehensive /ˌkɑm.pɹəˈhɛn.sɪv/

Cómo practicar con este vídeo

Escucha el vídeo entero una vez sin hablar y anota las palabras que no conoces.
Empieza a velocidad 0,75×, haz shadowing frase por frase y vuelve a la velocidad normal cuando te resulte fácil.
Grábate y compara con el original, prestando atención a palabras como custom, patch, database.

¿Qué es la Técnica de Shadowing?

Shadowing es una técnica de aprendizaje de idiomas respaldada por la ciencia, desarrollada originalmente para la formación de intérpretes profesionales y popularizada por el políglota Dr. Alexander Arguelles. El método es simple pero poderoso: escuchas audio en inglés nativo y lo repites en voz alta de inmediato, como una sombra que sigue al hablante con solo 1-2 segundos de retraso. A diferencia de la escucha pasiva o los ejercicios de gramática, el shadowing obliga a tu cerebro y músculos de la boca a procesar y reproducir simultáneamente patrones de habla reales. Las investigaciones muestran que mejora significativamente la precisión de la pronunciación, la entonación, el ritmo, el habla conectada, la comprensión auditiva y la fluidez al hablar, convirtiéndola en una de las metodologías más efectivas para la preparación del IELTS Speaking y la comunicación en inglés en el mundo real.

Técnica de shadowing: lee la guía completa paso a paso →

Shadowing Practice: Your API Can’t Handle Real-World Integrations - Learn English Speaking with Video

DRY Often Makes Your Code Worse

I Wrapped an API Into a Real SaaS (full build / step-by-step)

System Design Was HARD - Until You Knew the Trade-Offs

Tokens vs Variables in Tokens Studio for Figma | Variables Series

Azure App Service and Virtual Network Integration Options

Design a File Upload Service Like a Senior Engineer

IOC & Dependency Injection in Spring Boot - Quick Breakdown !! #shorts

Mini Project - Implementing a Simple Web Identity Federation Application

GENERATOR: Create More Success by Doing Less (Human Design Guide)

What Is REST API? Examples And How To Use It: Crash Course System Design #3

Armchair Architects: Resiliency in the Cloud – Core Patterns

8 Tech Choices to Lock In Before Agentmaxxing

Uber Data Engineering Mock Interview - Ride-Sharing Data Warehouse Schema