Martin is available for hire

Martin Zarza

Verified Expert in Engineering

Software Developer

Asuncion, Paraguay

Toptal member since September 26, 2022

Expertise

API Design Code Review Back-end Java API Development Python PyCharm Postman JavaScript REST APIs Full-stack Development Web Scraping Web Crawlers FastAPI Spring Boot

Bio

Martin is a back-end developer with a bachelor's degree in computer engineering and over four years of experience building and deploying large-scale web applications and APIs. Martin enjoys writing high-quality, high-performing code and primarily uses Python and Java, his favorite programming languages.

Portfolio

Ordermark

Python, FastAPI, Django, PostgreSQL, Redis, Celery, Amazon Web Services (AWS)...

Avery Dennison

Java, Spring Boot, JUnit, PostgreSQL, Docker, GitHub Actions, Git, Agile, Jira...

TAXit!

Java, Spring Boot, Python, Django, HTML, CSS, JavaScript, PostgreSQL, Docker...

Experience

Spring Boot - 5 years PostgreSQL - 5 years Java - 5 years Python - 4 years Django - 4 years Apache Maven - 4 years Docker - 2 years Django REST Framework - 1 year

Availability

Part-time

Preferred Environment

MacOS, PyCharm, DataGrip, Slack, Postman

The most amazing...

...thing I've built is an open-source library called jsifenlib that many local developers use to save time while working on projects.

Work Experience

Semi-senior Back-end Developer

2023 - PRESENT

Ordermark

Integrated our kitchen application with many DSP and POS systems to manage all the menus and orders from our client's restaurants.
Created APIs used by our own applications and also by our customers to manage everything related to their restaurants.
Built a dashboard that brings together all the financial information regarding the profits of the restaurants, independently of the DSP used.
Built unit tests to ensure the application kept working flawlessly after each modification.

Technologies: Python, FastAPI, Django, PostgreSQL, Redis, Celery, Amazon Web Services (AWS), SQLAlchemy, Pytest, Docker, Git, Jira, REST APIs, Postman, Code Review, Testing, Unit Testing, CI/CD Pipelines, Amazon S3 (AWS S3), API Design, API Development, Microservices Architecture, Back-end, API Integration, AWS Lambda, Microservices

Semi-senior Back-end Developer

2022 - 2023

Avery Dennison

Developed the 2nd version of an existing application used by brands in their factories worldwide.
Collaborated with other teams on integrating applications.
Built unit tests to ensure the application worked as expected after every modification.
Configured deployment workflows to deploy the application to our different environments continuously.

Technologies: Java, Spring Boot, JUnit, PostgreSQL, Docker, GitHub Actions, Git, Agile, Jira, JSON Web Tokens (JWT), REST APIs, Postman, Code Review, Testing, Unit Testing, Swagger, Pull Requests, Docker Compose, APIs, DevOps, Spring, Hibernate, SQL, Continuous Integration (CI), REST, Relational Databases, IntelliJ IDEA, Google Cloud Platform (GCP), CI/CD Pipelines, API Design, API Development, Microservices Architecture, Back-end, API Integration, Microservices

Semi-senior Full-stack Developer

2020 - 2021

TAXit!

Redesigned the web application used by over 4,000 customers to manage finances and taxes.
Implemented a payment gateway within the application so users could add their payment methods and pay for the provided service using the app.
Added new features to the web application used by other company departments.
Improved performance of different APIs used by our application to interact with government services.

Technologies: Java, Spring Boot, Python, Django, HTML, CSS, JavaScript, PostgreSQL, Docker, Beautiful Soup, Django REST Framework, Apache Maven, Git, Agile, Jira, REST APIs, Python Imaging Library, Postman, Django ORM, Code Review, Testing, Pull Requests, Requests, Asyncio, Web Scraping, APIs, DevOps, Web Crawlers, Automation Scripting, Spring, Hibernate, Linux, HTML5, SQL, Payment APIs, REST, Relational Databases, Ubuntu, Java 11, IntelliJ IDEA, CI/CD Pipelines, WebStorm, API Design, API Development, Full-stack Development, Back-end, API Integration

Junior Full-stack Developer

2018 - 2020

CBI Solutions

Developed a billing and invoicing web application for barber shops and beauty salons.
Configured new servers for clients, enabling them to support the growing number of active users.
Redesigned our web application, making it look more modern to attract new clients.

Technologies: Java, Spring Boot, HTML, CSS, JavaScript, PostgreSQL, MySQL, Apache Maven, Git, Agile, Jira, Code Review, Testing, Pull Requests, APIs, Spring, Linux, HTML5, SQL, REST, Relational Databases, Ubuntu, IntelliJ IDEA, WebStorm, API Design, API Development, Full-stack Development, Back-end

Experience

Jsifenlib – An Open-source Java Library

https://github.com/roshkadev/rshk-jsifenlib

Wrote jsifenlib, an open-source library in Java. It interacts with SIFEN, a web service released by Paraguay's government and used by companies to issue electronic invoices.

The library eases the implementation process for developers, allowing them to only provide functionalities instead of rewriting the entire code. I took over the project after the developer who started it left, continuing with the project as the sole developer and completing it.

TAXit! – A Web Application

Utilized Java and Python to create a web application used by customers to manage their finances and taxes. Users can upload photos of their invoices to create digital versions that can be accessed through the app and used to calculate taxes.

I was a full-stack developer and a part of a small team in charge of maintaining the application, adding new features that could benefit customers, and fixing bugs. Also, I headed the development of the app's third version and its redesign.

Sendit Telegram Bot – A Bot to Track Packages

Wrote and deployed a Telegram Bot in Python, that the user can use to track their packages coming from different parts of the world. Users can also receive notifications regarding their status.

At the moment, for personal use only.

Education

2018 - 2022

Bachelor's Degree in Computer Engineering

Universidad Autónoma de Asunción - Asunción, Paraguay

Certifications

OCTOBER 2020 - PRESENT

Server-side Development with NodeJS, Express and MongoDB

Coursera

Skills

Libraries/APIs

REST APIs, API Development, Beautiful Soup, Python Imaging Library, Django ORM, Requests, SQLAlchemy, peewee, Asyncio, Telegram Bot API

Tools

PyCharm, DataGrip, Postman, Apache Maven, IntelliJ IDEA, Git, Jira, Celery, Pytest, WebStorm, Gradle, Docker Compose

Languages

Java, Python, HTML, JavaScript, CSS, HTML5, SQL, Java 11

Paradigms

Testing, Agile, REST, Microservices Architecture, Microservices, Unit Testing, DevOps, Continuous Integration (CI)

Frameworks

Spring Boot, Django, Django REST Framework, JSON Web Tokens (JWT), Swagger, Spring, Hibernate, JUnit

Platforms

Linux, Ubuntu, Docker, Amazon Web Services (AWS), Linode, Google Cloud Platform (GCP), AWS Lambda

Storage

PostgreSQL, MySQL, Relational Databases, MongoDB, Redis, Amazon S3 (AWS S3)

Other

Code Review, Pull Requests, APIs, API Design, Back-end, API Integration, Web Scraping, Web Crawlers, Automation Scripting, FastAPI, Full-stack Development, GitHub Actions, Telegram Bots, Payment APIs, CI/CD Pipelines, Chatbots

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