Recent content on Daniel Mejía R.

 Problem 2 - Even Fibonacci Numbers
 
 
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 The problem statement asks to find the sum of the even Fibonacci numbers whose value is less than one million. 
 
 Fibonacci Series for even numbers
 
 
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 I’ll go short with this one. This is really popular and consist of the series 
$$
0,…

 Problem 1 - Multiples of 3 and 5
 
 
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 The problem statement asks to find the sum of all multiples of 3 and 5 not greater than 1000. 
 
 Bruteforcing solution
 
 
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 To bruteforce the solution it is enough to generate a list of multiples, prevent double counting and then perform the sum. In order…
I’ve been thinking on writing this for months since I came across an article called blogging in 2025 . Worked for three years in an AI-first startup, I switched from hand-made code solutions with AI assistance, to be the assistant reviewing AI generated code. I felt something was stripped out of me. Now that I see that AI generated content has flooded the internet, merchandise, and It is used to…

 Generators in Python
 
 
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 Sometimes when working with bulk data whose nature is somewhat unpredictable, such as a stream of events, or data chunks, or anything that can be batched, like in ETL pipilines where data passes across several transformation stages. My premise is that the process must work well within a constrained environment, either…
Recently I wanted to run jupyter from within a pyenv environment , and using the environment itself to have isolation of versions of the python modules installed. I was not satisfied with the blogs I found online so I tried my own approach. 
 First, I created a virtual environment using pyenv, 
 pyenv install 3.11.4
 pyenv virtualenv 3.11.4 chatbots-3.11.4
 pyenv activate
 pip…
This is a short story.
I was trying to use multer-s3 to perform uploads to Digital-Ocean-Spaces (DOS) using the AWS S3 protocol. It ended up failing to make things work with the things available and ended up implementing my own plugin to perform multipart uploads as an expressjs middleware. You can check the code here, 
 
 https://github.com/Daniel-M/multer-dos 
…

 Introduction
 
 
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 Recently got a SMS with a link to a phishing site intended to capture credit card
information. The way of doing it was a billing due to a stalled international delivery, and scammers were cautious enough so the phishing site redirected to the true deliverycorporation once the credit card information with the payment were…

 What is pyenv?
 
 
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 pyenv is a tool that lets you easily switch between multiple versions of Python, and it is really useful to work on python projects that require different python versions. If you are familiar with nvm the node version manager, pyenv follows a similar approach. 
Another big advantage of pyenv is the use of pyenv-vitualenv…

 Forewords
 
 
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 It is advisable to have high availability when serving data. We are considering debian GNU/Linux 10 during this process. With influxdb replication is achieved either by means of paying a managed influxdb instance, buying enteprise version, or implementing an influx-relay that offers bare-minumum high-availability. 
 In this…

 Forewords
 
 
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 This was tested using 3 different nodes with debian 10 GNU/Linux 
 A replica set in MongoDB is a group of mongod processes that maintain the same data set. Replica sets provide redundancy and high availability, and are the basis for all production deployments. 
 The primary node receives all write operations and records all…
I’ve been wanting to write about character sets and encodings for a while, since I had problems in the past understanding what is it all about? 
 
 Words and information
 
 
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 When reading this, all you are seeing is an arrangement of characters disposed in a certain way that they are meaningful to you. – for instance…
Recently I was working with hashing some files in order to take checksums to avoid
working with data-corrupted files received at the endpoint of a web server.
It sounds easy, receive the file, calculate the hash, and emit the response.
I only needed something like hash = calculate_hash(file) . 
A five minute research on duckduckgo lead me to write the following code, 
 import…
This is a short summary on how I managed to use the nvidia graphic card with my Debian Testing installation. I’ve cooked this blog since it may help other (and a future me) during their debian configuration stage 
 
 L’Entrée
 
 
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 Most Linux users are familiar with the hassle of making Nvidia GPU’s working with their linux…

 Notes
 
 
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 BigQuery(BQ) is Google’s serverless, highly scalable, enterprise data warehouse 
 SQL-like query language 
 Real time data analysis by “streaming ingestion” capability 
 Deals with gigabytes to petabytes of data volume 
 Offers data encryption and data access permissions via Cloud Identity and…
Concurrent computing is a form of computing in which several computations are executed during overlapping time periods—concurrently—instead of sequentially (one completing before the next starts). This is a property of a system—this may be an individual program, a computer, or a network—and there is a separate execution point or “thread of control” for each computation…
This post is part of a series of ESP32 blog posts. Look the index here 
 
 Motivation
 
 
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 In the last blog of the
series 
I wrote about freeRTOS tasks, and that the scheduler in FreeRTOS is designed to
provide a predictable execution pattern. The Tasks allow to design better
workflows for our applications, allowing to control…
This post is part of a series of ESP32 blog posts. Look the index here 
 
 Motivation
 
 
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 In the last blog post of this series,
we saw how to set up the basic development environment, then built and loaded
a hello-world program included in the examples folder of the esp-idf (Espressif IoT
Development Framework). Today I’ll…
This post is part of a series of ESP32 blog posts. Look the index here 
 
 Introduction (sort of)
 
 
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 The ESP32 was originally conceived by
 espressif a multinational company with
headquarters in Shangai, focused on developing cutting-edge WiFi-and-Bluetooth,
low-power, IoT solutions. Among our popular products are the ESP8266 and…

 Motivation
 
 
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 One of my hobbies during my school days was electronics after learning about
 B.E.A.M robots during a Popular
Mechanics for Kids episode. You can learn more about B.E.A.M. here 
 During my University years I had the opportunity to refine my knowledge on basic
electronics, and exploit my programming skills…
I’m not of an active blogger in this site, but you can take a look at
 http://blog.parallelo.ai and get in touch with
some of my work-related blog posts.

 What are continuous integration(CI) and continuous delivery(CD) systems?
 
 
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 According to Martin Fowler , one of the members of the Agile manifesto, Continuous Integration (CI), 
 
 is a software development practice where members of a team integrate their work frequently, usually each person integrates at least daily - leading to…

 Introduction
 
 
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 Exploration of http servers in Go. The packages under considerations are, 
 
 net/http 
 https://github.com/go-chi/chi 
 https://github.com/julienschmidt/httprouter 
 https://github.com/gorilla/mux 
 https://github.com/zenazn/goji/ 
 https://github.com/go-swagger/go-swagger 
…

 Link: https://www.pyimagesearch.com/2017/03/20/imagenet-vggnet-resnet-inception-xception-keras/ 
 
 
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 Key concepts:
 
 
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 CNN: Convolutional Neural Network 
 ImageNet dataset 
 ImageNet Large Scale Visual Recognition Challenge: train a model that can correctly classify an input…

 multiprocessing is a package that supports spawning processes using an API similar to the threading module.[1] 
 The Pool object which offers a convenient means of parallelizing the execution of a function across multiple input values, distributing the input data across processes (data parallelism).[1] 
 One should protect the “entry point” of the program by using if __name__ ==…

 General notes and remarks
 
 
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 Abreviations of interest, 
 
 WKB - Well Known Binary. 
 WKT - Well Known Text. 
 
 
 
 Introduction
 
 
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 GeoJSON is a geospatial data interchange format based on JavaScript Object Notation (JSON). It defines several types of JSON objects and…

 Reading guide
 
 
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 The text is accompanied with questions and observations at the end, such that notes of the form (Q#) correspond to the question number # on the list. In the same fashion (O#) indicates the observation number # . 
 
 
 Notes on Flask
 
 
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 http://flask.pocoo.org/ 
…

 Daniel’s log book
 
 
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 The site https://dalogbook.blogspot.com/ is my old blog, which I haven’t updated
since forever. Nevertheless I have lots of drafts soon to be published so stay tuned for updates.
Last updated: August 13, 2026
 
 
 Who am I?
 
 
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 Greetings! My name is Daniel, a passionate physicist, nerdy person, backend-focused full-stack developer. I see myself as a generalist software developer with experience in Machine Learning, LLMs and CNNs for Deeplearning.
What’s special about me is that I bring a unique blend of…
Last updated: August 13, 2026
 
 Hey, this is my now page , in summary I’m doing these, 
 
 After some life-changing events, I’m trying to go back to my fitness routine with Calisthenics for fitness and general wellness 
 Enjoying some months of career interruption after feeling burnt out in my last job, and other related life events 
 Studying software…