MongoDB Developer Day Belo Horizonte

2026-06-02T00:00:00+00:00

🍃 MongoDB Developer Day Belo Horizonte</h1>
Well, this article will be not so techinical, just some comments about the event I was invited to participate. As the title of the event already says, it's an entire day working with MongoDB, will be a mix of AI with MongoDB.
The good news is that was a hands-on experience. 🥳

🤪 This "article" will not have a good structure, I think it's better to call my notes. Some free notes that I was taking during the presentations. </blockquote>
🔎 Vector Search: Beginner to Pro</h2>
What is vector search? It's used to do a semantic search, this means that I will search by context. Meaning that will not only get data from the text itself.
The difereces between searchs:
Lexical search</th> Vector search</th></tr></thead>

Keyword search</td> Semantic similarities</td></tr>
You want to corpus closely matches how users search</td> "Vocabulary gap" between corpus and how users search</td></tr>
First pass at text-based relevancy</td> Text, image, audio, video search</td></tr> </tbody></table>

💡 Embeddings: numeric, mult-dimensional representation of a piece of information. </blockquote>
The data is embedded following a embedding model (machine learning model) to generate a vector of this information.
We will use at this event the Voyage AI embedding tool. It's a tool owned by MongoDB.
You need to choose the calculation to make the search. Some of them are: euclidean distance between the vertices of the vector, dot product vector multiplication as a measure of alignment, or cosine similarity. The cosine similarity is the most used by vector search, because it's measuring the angle between vectors.
One way to improve performance is to make a pre-filtering technique. This way it will use a small dataset to do a vector search. There is another way, the post-filtering, but it's not a good technique.
It is also possible to shrink the size of the embedding data on MongoDB, you can choose the quantization. The scalar quantization will change from float32 to int8. Binary quantization will decrease even more, making possible to use a single bit.
Links for vector search:

How to Choose the Best Embedding Model for Your LLM Application</a></li>
HSNW Deepdive</a></li>
Asymmetric retrieval using Voyage 4</a></li>
Quantization</a></li> </ul>
💽 Building RAG Applications with MongoDB</h2>
Retrieval-augemented generation (RAG) is a technique to enhance the quality of pre-trained LLM generation using information retrieved from external sources. It's a way to use AI but using a knowledge base.
The current top tier is AI agents, it has the knowledge base, but also has access to tools. The agent can execute some actions, for exemple: call a `ls</code> on my terminal.`
`Simples tasks are not required to have RAG, most of pre-trained models can handle those kinds of tasks. Making RAG being useful, when it's most specific tasks where I need to understand better the data.`
`Chunking: process of breaking down large pieces of text into smaller segments or chunks. </blockquote> Chunking strategies:`Fixed tokens: it's limited by a number; also possible to use with overlap</li> </ul> </li> Recursive with overlap: because it considers also paragraphs, punctuations, etc;</li> Semantic chunk: get all string to make sure it make senses (is not the most used).</li> </ul> Contextualized embeddings create a relationship between the chunks. Making possible to the LLM to get all context. ‼️ Always, always check if you are blocking anything that is not prepared to answer. Keep a guardrail so the anwser will not be of the track. </blockquote> To continue building a RAG application, it's important to persist this context. You need to understand which level of persistence you will need. Links: Chunking strategies</a></li> Contextualized chunkings</a></li> </ul> The A to Z of Building AI Agents</h2> The idea is to reconstruct the MongoDB chatbot</a>. It was some features: anwser questions based on the knowledge base and summarize the content. First thing first, what is an AI agent? An AI agent is a system that uses LLM to: reason through a problem, create a plan to solve the problem, execute and iterate on the plan with the help of a set of tools. The agent chooses which tool use, when call, and how to call. Components of an agent: Perception: collect informations about the environment, as an input;</li> Plan and reason: how to solve a problem and elaborate a plan to solve it, the LLM, also knew as an agent brain; Plan without feedback (Chain-of-Thought): LLM does not modify your execution plan;</li> Plan with feedback: the LLM will make some adjustments on the execution plan; ReAct (Reason + Act)</li> Reflection</li> </ul> </li> </ul> </li> Tools (actions): external interfaces to act and solve a problem, examples: getting info on wikipedia, database vector search;</li> Memory: help the agent to understand and learn with the past. Short term: specific chat;</li> Long term: about multiple chats.</li> </ul> </li> </ul> LangGraph</a> was be the library used to orchestrate the actions between the agents. Graphs has only three components: Nodes (logic): two nodes, one of the agent and another for the tools</li> Edges: define the workflow Fixed:</li> Conditional: like a decision tree;</li> Non-conditional:</li> Loops: return to a specific node using a custom logic for that.</li> </ul> </li> State: data structure shared between the nodes, to have relevant data to execute the task.</li> </ul> [START] -> [Agent Node] -> (conditional) -> [Tool Node] -> [Agent Node] -> ... -> [END] </code></pre> Links: Agent memory talk</a></li> </ul> That's all folks! Just to keep one more link here, you can check the MongoDB AI Learning HUB</a>. Avatar Legends: Cadê meus repolhos? (Parte 1) 2026-06-02T00:00:00+00:00 🥬 Avatar Legends: Cadê meus repolhos? (Parte 1)</h1> A movimentação nas Planícies da Grama Afiada estava um pouco estranha. Um homem havia acabado de sair da vila, ele parecia muito cansado, seus vestes estavam todo sujo e rasgado. Ele teve uma breve conversa com a senhora Qiang, a maior autoridade local. Apresentação dos personagens, aguardando jogadores. (texto ainda em rascunho) </blockquote> Qiang pediu ajuda aos camaradas para levar o jovem mercador de repolhos Zixin para o Monte Bao. Onde os camaradas Kaelik, Yuka, Morisokka e Zhu saíram das Planícies da Grama Afiada com Zixin e sua carroça de repolhos. O caminho até as montanhas ocorreu sem grandes problemas, eles revezaram para empurrar a carroça, passando por algumas pequenas vilas, e pontes. Ao chegar na montanha os camaradas se depararam com uma estranha neblina. Não havia o que temer, Zhu era um dobrador de água experiente, sabia como remover a neblina. Claro, depois de se esforçar para remover a neblina do caminho ela se intensificou. Kaelik agiu de prontidão, segurou Zixin por sua gola, enquanto Yuka não chegou a se afastar pois estava levando a carroça de repolhos. Morisokka um grande estrategista conseguiu se manter unido aos camaradas. Entretando, Zhu não conseguiu se manter junto. Separando-se do grupo. Após 30 minutos de caminhada o grupo se deu falta de Zhu, sem ter muito o que fazer optaram por seguir rumo ao Monte Bao. Zhu seguiu caminho, sem saber que estava sozinho. No horizonte conseguiu enxergar algumas formas. Se sentindo confortável avançou se deparando com uma senhora chamada Tia Hana, e dois irmãos do reino da água, Yan e Maly. "Olá meu jovem, poderia oferecer ajuda a uma senhora?" sem nem olhar aos seus companheiros, Tia Hana perguntou. O grupo, seguiu e parou em uma encruzilhada, onde avistou um grupo do reino da terra. Kaelik tentou negociar com eles, para que pudessem passar sem grandes problemas. Com muita intensidade o grupo correu atrás dele. Yuka preparou uma bola de fogo e tentou intimidar, o que parecia ter funcionado até que Kaelik tenta ajudar. "Vocês não possuem a capacidade de brigar com o Yuka." Kaelik esbravejou. Todos se engajaram em uma troca. Zhu viu o grupo de longe, e se preparou para o combate. Os irmãos começaram a atacar Zhu. Tia Hana havia sumido. Após uma intensa batalha, Yan foge. E os camaradas conseguem desmaiar os inimigos. A batalha não terminou muito bem, Zixin havia sumido. O mistério ficou. Na carroça havia um pedaço rasgado de tecido, aparentemente da tribo da terra. O que aconteceu com Zixin? Onde estão Tia Hana e os irmãos? Qual a relação entre eles? Ao menos uma alegria ficou, havia repolhos. Cookie 2025-07-31T00:00:00+00:00 Ingredients</h1> 125 g of unsalted butter at room temperature;</li> 3/4 cup os sugar;</li> 1/2 cup of brown sugar;</li> 1 egg;</li> 1 e 3/4 cup of flour;</li> 1 tea spoon of baking powder;</li> 300 g of chopped semisweet chocolate;</li> 1 tea spoon of vanilla essence.</li> </ul> 💡 Tip: to make chocolate cookie add 1/4 cup of cocoa powder. </blockquote> Directions</h1> Combine the butter, brown sugar, sugar, vanilla extract (and cocoa powder, if making chocolate-based cookies).</li> Gradually add the beaten egg and mix well.</li> Gradually add the flour and mix well (you can do this by hand or with a stand mixer).</li> Finally, add the baking powder and mix just until incorporated.</li> Once the dough is well mixed, add the chopped chocolate.</li> Form into small balls and bake in a preheated oven, on parchment paper, for approximately 15 to 20 minutes (250°C).</li> </ol> Git multi keys 2025-07-27T00:00:00+00:00 Another of fast paced configurations, this one is focused on have more ssh keys for different projects. I'm using my personal computer for work, well this implies different git access and configurations. We need to start creating the SSH keys</a> twice: ssh-keygen -t ed25519 -C "your_email@example.com" </code></pre> When I run the command above I usually save like: id_ed25519_personal</code> and id_ed25519_work</code>. Now you can add to the configuration. touch ~/.ssh/config </code></pre> And with your favorite editor put something like: Host github.com Hostname github.com User git IdentityFile ~/.ssh/id_ed25519_personal Host bitbucket.org Hostname bitbucket.org User git IdentityFile ~/.ssh/id_ed25519_work </code></pre> Since my company do not uses github, I just put the general hostname for that. Now it's a nice trick. Usually I've a global config for my email, but at the companies git it should use the corporate one. So, edit your ~/.gitconfig</code> file, and add: [includeIf "gitdir:~/Projects/work/**"] path="~/.work.gitconfig" </code></pre> Now, create the ~/.work.gitconfig</code> and put: [user] email = email@work.com </code></pre> Now everything from your work should be on the work folder, and everything there it will also have the .work.gitconfig</code>. Adding Swagger on Spring Rest 2025-07-08T00:00:00+00:00 ℹ️ This article is a simple step-by-step. </blockquote> Start adding the dependency on the pom.xml</code>. <dependency> <groupId>org.springdoc</groupId> <artifactId>springdoc-openapi-starter-webmvc-ui</artifactId> <version>${springdoc.version}</version> </dependency> </code></pre> After that you should create the configuration. On my example below I'm using everything as default, and scanning the package that I need. @Configuration @Import({ org.springdoc.webmvc.ui.SwaggerConfig.class, org.springdoc.core.configuration.SpringDocConfiguration.class, org.springdoc.webmvc.core.configuration.SpringDocWebMvcConfiguration.class, org.springdoc.core.properties.SpringDocConfigProperties.class, org.springdoc.core.properties.SwaggerUiConfigParameters.class, org.springdoc.core.properties.SwaggerUiConfigProperties.class, org.springdoc.core.properties.SwaggerUiOAuthProperties.class }) @ComponentScan(basePackages = {"org.springdoc"}) public class OpenApiConfig { @Value("${build.version}") private String buildVersion; @Bean public OpenAPI customOpenAPI() { return new OpenAPI() .info(new Info() .title("Lorem Ipsum API") .version(buildVersion) .description("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.")); } } </code></pre> It's important to remember to add the version on the application properties. As the example (application.yml</code>): build.version: @project.version@ </code></pre> This way the version will be read from the pom.xml</code>, meaning that you only need to change this at a single place. Now you can connect: localhost:${PORT}/${CONTEXT-PATH}/swagger-ui/index.html</code>. Git bash integration 2025-04-03T00:00:00+00:00 To make that works, you just need to have access to the terminal, and also to some text editor, like vim. We should add a funtion to check if you are at a git project, and return the branch. Git already provides a helper function for that __git_ps1</code>. For me it's not perfect because I don't want to have a space between my pc name and the $</code> character. To fix that, I created my helper at .bashrc</code>: # enable git branch name parse_git_branch() { if [[ -n "$(__git_ps1)" ]]; then echo "$(__git_ps1)" fi } </code></pre> This helper is pretty simple, it validates if I have any output with the git helper, if positive returns my branch. Then you can just update your ps1, or ps1 function like below: if [ "$color_prompt" = yes ]; then PS1='${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[01;33m\]$(parse_git_branch)\[\033[00m\]\$ ' else PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w$(parse_git_branch)\$ ' fi </code></pre> Yeah, I know this is not a big tutorial of how to make that, it's more a way that I can use later when I format my pc. 🤪 Binary Search in Java 2024-05-07T00:00:00+00:00 This article is part of a series about tech interview. Go to Tech interview</a> to read more. </blockquote> ⚠️ Since you are here I imagine that have a previous knowledge about programming, and programming language. If you don't know anything about this, maybe this article is not for you yet. Binary Search: an overview</h1> Today is Jane Doe birthday, you need to call her. You have at your hands a agenda with a lot of names, and phone numbers. If you go for alphabetical order, this will take quite some time. You need to go throw the entire list of names on A, B, C, yeah, you got it. You need to reduce the time need for that, and that is what the binary search is about. If you open the agenda and check the middle name, you can decide if you want to check names after that, or below that, only at this small change you will reduce the time at half. Doing this operation again, you will take half of the remaining half. A lot faster, but how much? The first example you need to check the entire agenda, this is what we call a sequential search resulting in $O(n)$ solution. The binary search has a $O(\log{}n)$ at the worst case. Just some quick comparation between both algorithms, where I add the value for n and the amount of steps: Algorithm</th> 10</th> 1 000</th> 1 000 000</th></tr></thead> Sequential Search</td> 10</td> 1 000</td> 1 000 000</td></tr> Binary Search</td> 4</td> 10</td> 20</td></tr> </tbody></table> Implementation in Java</h2> We start with the entire list of values: var low = 0; var high = sortedList.size() - 1; </code></pre> After that we check the value at the middle: int middle = (low + high) / 2; var item = sortedList.get(middle); </code></pre> Now we just need to decide if this value is higher, or lower than the one we are searching and continue from that. Now with the full code: public int search(List<Integer> sortedList, int target) { var low = 0; var high = sortedList.size() - 1; while (low <= high) { int middle = (low + high) / 2; var item = sortedList.get(middle); if (item.equals(target)) { return middle; } if (item.compareTo(target) < 0) { low = middle + 1; } else { high = middle - 1; } } return -1; } </code></pre> You can check the same code using generics at my GitHub</a>. Problems</h2> Ops this section is in progress. 🤪 What is SOLID? 2023-10-10T00:00:00+00:00 This article is part of a series about tech interview. Go to Tech interview</a> to read more. </blockquote> What is SOLID?</h1> SOLID is a acronym for five principles of Object Oriented Design, and stands for: S - Single-responsibility Principle</a></li> O - Open-closed Principle</a></li> L - Liskov Substitution Principle</a></li> I - Interface Segregation Principle</a></li> D - Dependency Inversion Principle</a></li> </ul> ⚠️ Here you will see only the main phrase about every principle. The best place to get this information is from the article The S.O.L.I.D Principles in Pictures</a> wrote by Ugonna Thelma. Single-Responsibility Principle (SRP)</h2> A class should have one, and only one, reason to change. (Martin, n.d.) </blockquote> The idea behind the Single-Responsibility Principle (SRP) is that a class or module has a single responsibility or task to perform (Boris, 2023). Open-Closed Principle (OCP)</h2> You should be able to extend a classes behavior, without modifying it. (Martin, n.d.) </blockquote> Liskov Substitution Principle (LSP)</h2> Derived classes must be substitutable for their base classes. (Martin, n.d.) </blockquote> Interface Segregation Principle (ISP)</h2> Make fine grained interfaces that are client specific. (Martin, n.d.) </blockquote> Dependency Inversion Principle (DIP)</h2> Depend on abstractions, not on concretions. (Martin, n.d.) </blockquote> References</h1> Oloruntoba, Samuel. (2020, September 21). SOLID: The First 5 Principles of Object Oriented Design. Digital Ocean. <https://www.digitalocean.com/community/conceptual-articles/s-o-l-i-d-the-first-five-principles-of-object-oriented-design</a>/></li> Martin, Robert C. (n.d.). The Principles of OOD. butUncleBob. <http://butunclebob.com/ArticleS.UncleBob.PrinciplesOfOod</a>/></li> Bodin, Boris. (2023, September 9). Understanding SOLID Principles. Scub-Lab.<https://lab.scub.net/understanding-solid-principles-9a0181e68b88</a>/></li> Thelma, Ugonna. (2020, May 18). The S.O.L.I.D Principles in Pictures. Ugonna Thelma.<https://medium.com/backticks-tildes/the-s-o-l-i-d-principles-in-pictures-b34ce2f1e898</a>/></li> </ul> Object-oriented programming (OOP): an overview 2023-07-30T00:00:00+00:00 This article is part of a series about tech interview. Go to Tech interview</a> to read more. </blockquote> ⚠️ Since you are here I imagine that have a previous knowledge about programming, and programming language. If you don't know anything about this, maybe this article is not for you yet. Object-oriented programming (OOP): an overview</h1> Object-oriented Programming (OOP) is a programming paradigm that relies on concept of classes and objects (Nyakundi, 2022). Those concepts and the paradigms of OOP will be more explained in details. Class vs Object</h2> When we model a problem in terms of objects in OOP, we create abstract definitions representing the types of objects we want to have in our system (Mozilla, n.d.). Those abstract definitions is what we call a class. Let's imagine that we will create a trading card game (TCG). To make that we need some rules, and those rules are shared between the game. One of those rules are the cards entity, like the example below: public class Card { private final String name; private final String description; private final int attack; private final int defense; /* constructor and getters */ /** * Check if this card is destroyed by the attacker. * * @param Card attacker card / public boolean isDestroyedBy(@NotNull final Card card) { return card.getAttack() > this.defense; } } </code></pre> Ok, I know that the Card have those variables and methods. Know I need to instantiate with data from real world. var knightOfKeyboard = new Card("Knight of Keyboard", "This programmer is a gentleman that always carry her own mechanical keyboard", 850, 900); var pmOfChaos = new Card("Project Manager of Chaos", "Where this Project Manager go the place becomes a mess", 1200, 1000); if (knightOfKeyboard.isDestroyedBy(pmOfChaos)) { System.out.println("Your card was destroyed"); } else { System.out.println("Your defense is better"); } </code></pre> Those variables with the card is what we call an object. TL;DR: Class is a template, containing variables and methods. Object is the instantiated class. Paradigms of OOP</h2> Now that you read about the difference between class and objects, it's also important to know some paradigms of OOP. Inheritance</h3> Our TCG is going on fire, but the players are talking that we have only character card. They are asking for another type. We will have know two types of cards: character card and app card. They share some variables and methods, but not all. To make simple and don't repeat code, we will use one of the OOP paradigms, the inheritance. abstract class Card { private final String name; private final String description; / constructor and getters / } class CharCard extends Card { private final int attack; private final int defense; / constructor and getters */ /** * Check if this card is destroyed by the attacker. * * @param Card attacker card / public boolean isDestroyedBy(@NotNull final Card card) { return card.getAttack() > this.defense; } } class AppCard extends Card { private final int modifier; / constructor and getters */ /** * Apply modifier at some character card. * * @param Card card thaw will be modified / public void modify(@NotNull final Card card) { // TODO implement } } </code></pre> With the AppCard</code> we can modify some information at the CharCard</code>. Both of them is a Card</code>. We can say that Card</code> is a superclass or parent class of both CharCard</code> and AppCard</code>. Also we can say that CharCard</code> and AppCard</code> are subclasses or child classes of Card</code>. We can shuffle both types at our deck, because both are subclasses of Card</code>. Encapsulation</h3> This concept we are already using since the first example, let's see again: abstract class Card { private final String name; private final String description; / constructor and getters */ } </code></pre> See, we let only the responsible for the data to manipulate that. Only Card</code> have access to the data name</code>. This is what this concept is about. Encapsulation refers to the bundling of data and methods that operate on that data within a single unit (Geeks for Geeks, n.d.). We are hiding the implementations details, so the outside can't see how it works, but can interact with the data by methods. Abstraction</h3> The abstraction concept refers to the process of hiding the internal details, just describing things in simple terms. We can take the List</code> for example, we have some methods like add</code>, but we don't know how it is implemented. We jus now that if we call this method sending some data as parameter, this data will be present at the list at the end. Polymorphism</h3> Polymorphism is the concept where an object behaves differently in different situations. There are two ways to achieve that, by overriding, or overloading. Difference between Override, and Overload</h4> Override means that you will write a new behavior. Occurs on run-time. To understand, let's go back to our card game, let's make a small change to the Card</code> class, adding a toString</code> method abstract class Card { // .. public String toString() { return name; } } </code></pre> Yeap, nothing to drastic, but for the CharCard</code> this is too shallow, we need more information. To make this, we will Override the toString</code> method. class CharCard extends Card { // .. public String toString() { return String.format("%s: %d/%d", name, attack, defense); } } </code></pre> Every call to toString</code> from CharCard</code> will have this new information, but the behavior of Card</code>, or AppCard</code> will be the same, since we didn't changed there. But the overload is different, we can add new methods with the same name, but different parameters. For example, we are able to create two different constructors and still valid. We can choose which one we want at different places. class Deck { private final List<Card> cards; public Deck() { cards = new ArrayList<Card>; } public Deck(List<Card> cards) { this.cards = cards; } // getter } </code></pre> Also, the overload happens at compile-time. TL;DR: Override: Keep method signature, but change behavior</li> Overload: Two or more methods with same name, but different parameters</li> </ul> References</h1> Nyakundi, Hillay. (2022, September 6). OOP Meaning - What is Object-Oriented Programming?. freeCodeCamp. <https://www.freecodecamp.org/news/what-is-object-oriented-programming/</a>/></li> Mozilla. (n.d.). Object-oriented programming. MDN Web Docs. <https://developer.mozilla.org/en-US/docs/Learn/JavaScript/Objects/Object-oriented_programming/</a>/></li> Geeks for Geeks. (n.d.). Encapsulation in Java. Geeks for Geeks . <https://www.geeksforgeeks.org/encapsulation-in-java/</a>/></li> </ul> Tech Interview 2023-07-30T00:00:00+00:00 Interviews is also part of being a programmer (or almost anything), here you will see a compiled of articles to help you at this path. ⚠️ WARNING This article is UNDER CONSTRUCTION. Programming</h1> This is not only algorithms and data structures topics, must also cover the basics of programming, with topics such as: Object-oriented programing (OOP)</a></li> Design Patterns</li> Clean code</li> SOLID</a></li> </ul> Algorithms and Data structure</h2> Binary Search</a></li> </ul> System Design</h1> Client-Server Model</li> Network Protocols</li> Storage</li> </ul> Version</h1> (2023/07/30) 🎉 Starting this project, with a few topics that I will write.</li> (2023/10/10) 🪨 Added SOLID article link.</li> (2024/05/07) 🔎 Added binary search article link.</li> </ul> Tool Tips #1 2022-08-14T00:00:00+00:00 Preface</h1> The tooltip, ... is a common graphical user interface (GUI) element in which, when hovering over a screen element or component, a text box displays information about that element. Wikipedia</a>, read on 2022-08-14 </blockquote> I just tried to make some fun about the name, but to be more precise the title should be something more like "Tools that might help you too". It is an article where I'll show some useful software to do something. Yeah, pretty generic, right? In this article, I'll show two apps that I use. The first one is about formatting a PC. It's something trivial that we usually do over time, when we update to a new version of the OS, or maybe when we want to try a different Linux distro. Last but not least, I'll show a package manager for Windows. Bootable USB drive with simple steps to update</h1> I have already formated a lot of USB sticks to put another Linux distro or version of Windows in it. It takes time and it's boring to do it every time: you install some software to help you create a bootable USB stick, or follow the commands with the terminal. To solve this, I've discovered Ventoy</a> and it's a lifesaver. After installing it in one USB drive, I just need to add the ISO to the right partition, and voilà, it's ready! Example of the selection of ISO when booting through Ventoy: Install and update all your programs at once</h1> </a> This software, called Ninite</a>, is a masterpiece made for Windows OS. It will help you install a lot of software with a single click. You just have to select the programs you want to install and Ninite will create a very small installer file for you. Plus, it will automatically reject all toolbars when installing the software. Run the Ninite installer and it'll install all the programs you selected. Simple like that. Git Submodules, an Overview 2022-08-08T00:00:00+00:00 Preface</h1> My first contact with the submodule was a happy accident when looking at how to create my blog. Reading the Zola</a>'s documentation. It was recommended to use when adding a new theme to the project. With the flow to update, fix, and improve my blog, I had some issues understanding how the submodule works. So, I've decided to create this article with some information. Enjoy. What is a submodule?</h1> The submodule allows you to add another git project inside your project. But why? Have you ever tried to get some project to your project? Probably the approach will be: download the repository (zip file) and unzip your project. If you need to update, you'll do it everything again. Seems like a lot of work, and the submodule will remove for you. This submodule will not be pushed with your commits. And when downloading the project will also download the submodule. The update will be one git command. But it's not just that. You will be able to keep your custom codes in the library, making it easy to merge when a new version comes out. Adding a Submodule</h1> The command to add a submodule is a simple line: git submodule <url> <name> </code></pre> Ok, you need more information before continuing. The URL is a git endpoint to download the project. And the name is how you want to have this submodule called on your project. Example: git submodule https://github.com/gscavalcante/apollo.git themes/apollo </code></pre> This execution will create a folder themes/apollo</code> with the content of this repository in the last commit at the root of your project. Since my example have a name separated by a slash (/), it will create a folder with the submodule inside. . ├── README.md ├── content │ └── about.md ├── sass ├── static ├── templates └── themes └── apollo 6 directories, 2 files </code></pre> Now you can use everything from this project on your own. Adding From a Branch</h2> Another way to add the submodule is with a branch, so it'll not stay at a specific SHA1 when updating. To accomplish this git submodule -b <branch> <url> <name> </code></pre> But if you already have the submodule added, you can change the .gitmodules</code> file, for example: [submodule "<name>"] path = <path> url = <url> branch = <branch> </code></pre> Add the option branch with the one you want to get this submodule. Update a Submodule</h1> Update from a remote repository is easy when you track with a branch. For this, run the command below: git submodule update --remote </code></pre> If your submodule is not following from a branch, then go back and read Adding From a Branch</a>. How to Delete a Submodule</h1> git rm <submodule-name> </code></pre> But the old directory will stay at .git/modules/<path-to_submodule></code>. Delete this folder, and you can download another submodule with the same name without a problem. rm -rf .git/modules/<path-to_submodule> </code></pre>

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Git multi keys

Adding Swagger on Spring Rest

Git bash integration

Binary Search in Java

What is SOLID?

Object-oriented programming (OOP): an overview

Tech Interview

Version</h1>

(2023/07/30</em>) 🎉 Starting this project, with a few topics that I will write.</li>
(2023/10/10</em>) 🪨 Added SOLID article link.</li>
(2024/05/07</em>) 🔎 Added binary search article link.</li> </ul>

Tool Tips #1

Git Submodules, an Overview

Gabriel Cavalcante

MongoDB Developer Day Belo Horizonte

Gabriel Cavalcante

MongoDB Developer Day Belo Horizonte

Avatar Legends: Cadê meus repolhos? (Parte 1)

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Git multi keys

Adding Swagger on Spring Rest

Git bash integration

Binary Search in Java

What is SOLID?

Single-Responsibility Principle (SRP)</h2> A class should have one, and only one, reason to change. (Martin, n.d.)</p> </blockquote> The idea behind the Single-Responsibility Principle (SRP) is that a class or module has a single responsibility or task to perform (Boris, 2023).</p>

Open-Closed Principle (OCP)</h2> You should be able to extend a classes behavior, without modifying it. (Martin, n.d.)</p> </blockquote>

Liskov Substitution Principle (LSP)</h2> Derived classes must be substitutable for their base classes. (Martin, n.d.)</p> </blockquote>

Interface Segregation Principle (ISP)</h2> Make fine grained interfaces that are client specific. (Martin, n.d.)</p> </blockquote>

Object-oriented programming (OOP): an overview

Tech Interview

Version</h1> (2023/07/30</em>) 🎉 Starting this project, with a few topics that I will write.</li> (2023/10/10</em>) 🪨 Added SOLID article link.</li> (2024/05/07</em>) 🔎 Added binary search article link.</li> </ul>

Tool Tips #1

Preface</h1> The tooltip</strong>, ... is a common graphical user interface (GUI) element in which, when hovering over a screen element or component, a text box displays information about that element.</p>

Git Submodules, an Overview

Version</h1>

(2023/07/30</em>) 🎉 Starting this project, with a few topics that I will write.</li>
(2023/10/10</em>) 🪨 Added SOLID article link.</li>
(2024/05/07</em>) 🔎 Added binary search article link.</li> </ul>