Articles

Avoid try/catch hell without going full functional

Recently I’ve been collaborating with a team in a decently large and complex Java codebase with more than a couple of years in production. The codebase has gone through various business changes and has quite a lot of edge cases to consider. Most of the code was done by people that are no longer in the company and. Consequently, defensive programming is quite prevalent. As you might expect, Exceptions are thrown everywhere, and the code is riddled with try/catch blocks where the catch blocks effectively act as if/else statements,

Published on 2024/10/29 by Eric Driussi

Maintainable Failed Rows SQL Queries for soda.io

In this article, we saw the importance of having good data quality, and how to use soda.io to monitor it, covering the checks by a concrete unit testing strategy. Among the possible checks, we saw the possibility of checking the failed rows of a table. In this article we will see how to refactor the SQL queries to make them more maintainable with a pattern where we will be able to see different parts of the query in a more clear way (building, errorsRows and reportedRows).

Published on 2023/11/09 by Mario S. Pinto Miranda

Soda Checks Development With Test Driven Development

Data quality is probably the biggest concern in any organization that works with data to build models with artificial intelligence, use it for business intelligence, or generate data automatically for some use cases. In this sense, it is required to create a network of validations around the output dataset of any process in the data pipeline. The first approach is to perform a manual data analysis with notebooks in order to detect defects.

Published on 2023/07/06 by Mario S. Pinto Miranda

The value of the community

The professional community plays a crucial role in the development of our industry. During Socrates Canaries 2023 (Socracan), we hosted a discussion on what constitutes a healthy community. What are the values of the community we want, what are the various actors involved and what’s their expected contribution.

Published on 2023/06/26 by Carlos Blé Jurado

How to publish your Python project documentation on Read the Docs

Introduction In our day-to-day work, we collaborate on a Python project, which consists of a library that we want to make open source. After several months of work, we reached the current stage of publishing the library, and we also needed to publish the documentation that we generated with Sphinx. After some research, we realized that most well-known Python libraries publish their documentation on Read the Docs. In this article, we will explain what Read the Docs is, how it works, and we will provide an example of how you can integrate it into your project.

Published on 2023/04/05 by María Guerra Suárez and Ana Cáceres

Events in Solidity

In this article, we will use the terms “Events” and “Logs” to refer to the same concept. In Ethereum, one term or the other is preferred depending on the context (for example, “logs” in the EVM and “events” in Solidity). However, since both terms are interdependent and one is a consequence of the other, we will use them interchangeably to refer to the same thing. What are they? In Solidity, events can be considered as an abstraction of the logs that the EVM uses to store information in an indexed data structure known as Bloom Filters1.

Published on 2023/03/02 by Fran Palacios

Storage in Solidity

In this article, we’re going to delve a bit deeper into persistent storage on EVM-compatible blockchains1. In other languages, it’s not necessary to know what happens at a low level in order to write efficient code, but in the case of Solidity (which is not quite a high-level language), it is important – though not essential – to know this, because operations cost gas. Gas is the unit that measures the amount of computational effort required to execute operations on the blockchain.

Published on 2022/10/19 by Fran Palacios

Clean your tests with Kalia Vanish

Recently, we have encountered the classic situation with which more than one of us feels identified. When we are writing code, they suggest an improvement and we think: Ah, that’s right, we hadn’t thought of that! Going to the test code, and finding a bunch of data in the given section, can be painful. Data that makes noise, or messes you up more than it should, since most probably your program logic does nothing with it, it just adds it and/or checks that it is in the output.

Published on 2022/10/17 by Airan Sánchez Brito

Tips for technical interviews

Among the many services we offer to our customers, we help them improve the way they conduct technical interviews in their search for developers. Everybody is looking for developers, for senior developers to be precise. We do conduct interviews too, all the people working at Lean Mind went through our process at some point. There are at least two interviews, one that is non-technical with the aim to get to know the candidates, their values, dreams and aspirations, as well as communication skills.

Published on 2021/10/21 by Carlos Blé Jurado

The importance of giving and receiving feedback

These last few weeks I’ve been reading a book related to feedback to learn more about this topic. The book is called Smart Feedback and their authors are Jane Rodriguez, Rosa Rodriguez and Noemi Vico. I would like to share what I have learned and how important it is to give and receive feedback both on a personal and organizational level. As people, we have different experiences, perceptions and histories and the truth is that many times we take all this as a basis to relate to others and deliver a judgment or opinion.

Published on 2021/08/18 by Juan Antonio Quintana

AndroidSecurityConfig for local development and useful commands

In one of the projects we have been working on for the last months we’ve been working on both mobile development (native Android) and web development, creating a backend and a front end application. Basically, the mobile app sends messages via POST request to the backend, where they are stored, so they can be displayed in the frontend dashboard we created as well. Android does not trust unsecure connections (HTTP instead of HTTPS) by default.

Published on 2021/07/30 by Iván Santos González and Mireia Scholz

Configuring a Zoom meeting room for the team

At the time of this writing, Zoom is definitely our preferred choice when it comes to videoconferencing. It’s been our choice for the last two years or so. Something that works very well for every team/project is to configure a Zoom room that is permanently open so that any team member may pop up at anytime and find the others.

Published on 2021/02/03 by Carlos Blé Jurado

Dear reader, this website does not track you

The cookie warning notice is really annoying, specially when you don’t have other choice than accepting them to read a website. Moreover, if you value privacy what is even more annoying is to be tracked everywhere you go on the Internet.

Published on 2021/01/04 by Carlos Blé Jurado

Functional Operators

Array Refactoring Patterns You may have probably heard of functional programming many times, however, if you are starting in the world of development or you come from object oriented programming, you will not know with certainty what it is about. Let’s begging with a basic definition, since the aim of this term is creating a functionality based on programming methods, it receives a few entries params, in order to return a value, at this stage it doesn’t exist side effects, it means that values are immutable.

Published on 2021/01/04 by Adrián Ferrera González

Why you should use ArchUnit

Once upon a time, there was a legacy project. One can see the right architectural design patterns shaped into the application’s modules. The domain held the correct logic. The interaction with the database and system inputs were appropriately encapsulated. However, once you start digging into the code, several features spread the logic across all layers: There were database entities in the Controllers, Transactions everywhere, incorrect use of the ORM with hardcoded SQL, cyclic dependencies, etc.

Published on 2021/01/04 by Leanminder Anonymous

Code with me - Plugin pairing for IntelliJ

Code with me is a new functionality that JetBrains has recently brought like a novelty to IntelliJ. It is a plugin that allows us to pair programming with more than one partner, as if we were writing in Google Docs in a collaborative way.

Published on 2020/12/15 by Rubén Zamora

Is Git the best VCS ever?

Git has become the software industry de facto standard version control system. It was created by Linus Torvalds to support the singular development of the Linux Kernel, however it has been adopted by most open source projects as well as the corporate world. Does that mean it’s the best tool ever?

Published on 2020/11/18 by Carlos Blé Jurado

The big impact of the small coding decisions

Maintainable code requires the programmers to make conscious decisions about code design at the smallest level, because the code is not ruined in a single day but over time, when unconscious or bad decisions are made day after day.

Published on 2020/06/20 by Carlos Blé Jurado

Lean Mind's School

Since the very beginning, Lean Mind have been collaborating with local universities and high education institutions in the education of young developers. We take interns for a few months to help them learn coding practices and principles as well as soft skills. They are required to spend around three months in a company they choose in order to get their degree. This happens once or twice a year.

Published on 2020/06/01 by Carlos Blé Jurado

Workshop: Inner Team Talent Tools

We are happy to count on Rosa Elvira Gonzalez as our psychologist and coach at Lean Mind. She’s been running workshops and team activities for us since the beginning of our company. From team building activities to emotional intelligence training, one-on-one meetings and much more.

Published on 2020/06/01 by Carlos Blé Jurado

Organising test fixtures with Gradle

It’s recommended to separate integration tests from unit tests for several reasons. One is to shorten the feedback loop as the unit tests run way faster. In the case of a Java project using Gradle, it’s very common to split the project into multiple sub-projects, such as, common, model, application …

Given this configuration, it could be difficult to have a helper class used by the unit and integration tests in the various sub-projects. As this is a test helper, we are not interested on having it next to the production code and we don’t want to copy the class to several sub-projects.

Published on 2020/05/17 by José Luis Rodríguez Alonso

The Lucky Organiser: SoCraTes Canaries (Socracan) 2020

When I first met Carlos in 2003 and he repaired my computer (it was part of his job at that time), I told him that he had to be proud of working on what he had been studying for… He explained me that he was not and I learned that a computer engineer is not the one who fixes the household appliances… Although I still blame him when the router doesn’t work or the karaoke crashes haha.

Published on 2020/02/13 by Dácil Casanova

Mocking Functional React Components

Most of the time you either mount the component including all its inner components in order to test it or instantiate a shallow version of it. Sometimes however you need a mix, mounting the component for real except for one piece. This is when you need to mock out an inner component to spy on it or stub it’s behaviour.

Published on 2019/08/15 by Carlos Blé Jurado

Testing Functional React Components

React Hooks is simplifying the way we handle state and logic within our components. I am glad I don’t need Redux’s complexity to implement simple components that perform simple tasks. The new React (from v16.8) is easier to test than ever, although there are so many approaches to testing and so many tools out there. What is your favourite strategy? In this post we tell you mine.

Published on 2019/08/07 by Carlos Blé Jurado

Answers to your questions on TDD and testing

I published my humble book on TDD in Spanish nine years ago. I started writing it around this time, ten years ago. I definitely want to publish an updated revision of the book fixing the many mistakes I made into it, using examples that are more concise and even using JavaScript for some of them rather than C#.

Published on 2019/01/02 by Carlos Blé Jurado