The Dev World – Sergio Lema

All Articles

  • Python Logging

    Python Logging

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    by

    Sergio Lema
    in

    In this article I will show how to use the Logging library in Python. I will show how to configure the Logging library for many Handlers, Formatters and Filters.

  • Spring Cloud Sleuth & Zipkin

    Spring Cloud Sleuth & Zipkin

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    by

    Sergio Lema
    in

    In this article I will show how to trace requests between microservices using Spring Cloud Sleuth and Zipkin. Spring Cloud Sleuth will help me identify the logs from a single request between all the microservices. And Zipkin will show me the elapsed times at the microservices.

  • Spring Security and Roles Authorization

    Spring Security and Roles Authorization

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    by

    Sergio Lema
    in

    In this article I will explain the difference between Authentication and Authorization. I will also explain how to implement the Authorization pattern with Spring Security. For that, I will use the @PreAuthorize annotation.

  • Spring Batch

    Spring Batch

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    by

    Sergio Lema
    in

    In this article I will show how to create a complete Spring Batch project. I will show how to configure a Job and the Steps. I will implement a Step with a reader, processor and Writer. I will implement another Step with a Tasklet.

  • Jinja Templates

    Jinja Templates

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    by

    Sergio Lema
    in

    In this article, I show how a Flask backend can render and return Jinja templates. I will show how to use variables inside the Jinja templates, blocks and macros.

  • Optimizing Joins with CTE

    Optimizing Joins with CTE

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    by

    Sergio Lema
    in

    This week, I faced a problem with the performance of a query in PostgreSQL. I came from a cardinality result of more than 70.000.000 rows with a time response of 3 minutes to only 10 seconds.

  • Python Pre-Commit

    Python Pre-Commit

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    by

    Sergio Lema
    in

    In this article I show how to configure pre-commit in a Python project to format and check the code. I will show 4 tools which will run automatically with the Git hooks.

  • The CSRF Protection with Spring Security

    The CSRF Protection with Spring Security

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    by

    Sergio Lema
    in

    In this article I will explain the CSRF attack, the Cross-Site Request Forgery attack. I will show how Spring Security can protect against this attack, in both a server side rendering server and with a separated frontend and the Cookie repository.

  • MongoDB with Spring Data

    MongoDB with Spring Data

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    by

    Sergio Lema
    in

    In this article I show how connect a Spring Boot application with MongoDB. I will show how to configure a Spring Boot application to be connected to a single noSQL database as MongoDB. And I will show how to use Spring Data to request a MongoDB database.