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Sandro Fernandes
Verified Expert in Engineering
Back-end Developer
Sandro is driven by a uniquely strong dedication: he has been an entrepreneur from an early age. With extensive experience developing sustainable solutions and a love of learning new technologies, he constantly seeks new challenges and new opportunities to excel.
Portfolio
Experience
Availability
Preferred Environment
GitHub, MySQL, jQuery, Python, PostgreSQL, React, Django, NGINX, Ubuntu, TypeScript
The most amazing...
...solutions I've coded are a logo interpreter written in 120 lines of code, a barcode reader on a joystick port, and a full text search for the Hebrew language.
Work Experience
Full-stack Django and Node.js Developer
Karaite Jews of America Inc
- Extracted biblical text from Word docs, HTML, and spreadsheets, and compiled a database with those texts.
- Added audiobooks to books. A record of the text is added to each book, each book has a chapter and verse or paragraph that has a start and end timestamp. We can display the text being chanted in sync with the song.
- Created back-end APIs and a React front end to display, search, and play out loud biblical texts in Hebrew and English.
- Developed all infrastructure from scratch using Ubuntu, Django Nginx, PostgreSQL, and Bash.
- Created an inverted index for the Hebrew language in order to search those texts. The English search was done with a PostgreSQL full-text search.
- Added text to speech for biblical books in Hebrew and English so that one can listen to the text.
Full-stack Developer
Toptal Clients
- Developed several applications for international companies, from a simple REST app that took three days to develop to a project spanning eight months.
React Developer
Isaac Shrem
- Developed an AI-driven audio/video analysis application, based on which the user may select parts of the video/audio and create new videos/audios in various formats, including VTT, SRT, and GIF.
- Created a back-end API to be used by the application.
- Set up account management, creating super users who can admin accounts and videos/audio content via an app. Users had individual accounts, allowing them to upload and download videos.
- Used a one-time code for authentication that is sent by email and lasts for five minutes. No passwords are stored on the database.
- Implemented task queue to manage video/audio processing.
Back-end Engineer
Meadowstone Farm, LLC
- Enhanced the current application by fixing bugs and adding new features.
- Updated the current stack to the last versions, Ubuntu, Conda, Django, Nginx, Supervisor, and Gunicorn.
- Cleaned up code on the back end, removing more than 2000 lines of code.
Lead Software Engineer
Dane Roth
- Developed a new authentication system, using a single expiring key.
- Solved the CSS site injection that changed the site's look and feel after the extension was activated.
- Saved lots of money in the long run by changing the back-end infrastructure. There was a better performance by removing calls between data centers and concentrating all on one data center.
Full-stack Engineer
EZ PTZ AS
- Developed the back and front end from scratch using Django, React PostgreSQL, Nginx, and Ubuntu.
- Worked on the proprietary hardware and software system to do remote inspections. One should buy the hardware (cameras) and a license to use the system. Licenses vary in the number of users and lifespan.
- Used Twilio, a room to set to gather users and control a remote camera.
Lead Software Engineer
Solvency II Wire Ltd
- Designed the application that efficiently processes PDFs containing financial data, extracting the relevant information, and seamlessly integrating it into a Postgres database.
- Created the front-end display of this data as charts, fully searchable and configurable.
- Contributed to the main objective of presenting a clear and comprehensive overview of insurance companies' performance, including side-by-side analysis.
CEO, Lead Developer, DBA
Guiadobebe.com.br
- Developed a website with two million unique visitors, seven million page views, and a million emails sent per month.
- Implemented a MySQL database schema with a high availability design in mind.
- Developed a CMS in Django tailored to Guiadobebe's needs.
- Installed and configured secure Linux servers back end.
- Developed applications and improved the site's SEO.
Founder
Softrent Automação Comercial ltda.
- Pioneered the use of barcodes in Brazil.
- Worked as chief developer and organizer.
- Led the development of solutions for video rental stores, for many years.
- Gained experience in running a company as a CEO, managing finances and making the main decisions.
- Trained more than a hundred employees.
- Performed consulting jobs for many companies.
Computer Science Teacher (pro bono)
American School in São Paulo
- Taught teenagers the fundamentals of computer science.
- Used Lego Mindstorms to help students learn basic computing.
- Used a 8086 emulator to demonstrate how a microprocessor works.
- Used Delphi to build small Windows programs illustrating logic, program flow, output, and more.
- Graded students by skill level.
Experience
Audio and Video App
Karaites Learning Center
http://kjlc.karaites.orgSome challenges were enabling full-text search in Hebrew and synchronizing Hebrew audio books with text.
I was the developer from the start to the end of the project. I was involved in the back and front ends, server config, and installation.
Stack: Django, Python, Nginx, PostgreSQL, React, TypeScript
This was an open source project.
Back End to a POS
http://www.meadowstonenh.com/I collaborated with another engineering team member, and I developed the front-end.
The server resources here are optimized, reducing the monthly bill by 60%.
The dead code was removed.
An improved Django admin was developed so that users add more control.
Updated all stacks for the current version.
Stack used: Django, NGINX, Gunicorn, PostgreSQL, Supervisor
Making Surveys Greener
http://hub.ezptz.noThe system is composed of proprietary hardware, mainly video cameras, and software that runs in a browser.
Stack: Django, Django REST Framework, SQLite/PostgreSQL, React, Twilio API, Shopify API
Dane Roth
http://carpebrutus.com/Stack: Django for the back end, jQuery and vanilla JavaScript for the front end, PostgreSQL as the relational data, Redis as cache, and Heroku as the hosting provider.
Survey System (via Toptal)
To incentivize the drivers to post, a fee is paid for each week that the drivers upload images. To upload, the driver must have an account. Payments are made using a PayPal account.
Stack: Flask, React, MongoDB, Heroku, mLab
IDS Consulting (via Toptal)
Stack: Django, REST Framework, Vue, Vuex, SQLite, Heroku
Challenge Your Understanding (via Toptal)
The user may participate in debates—all are moderated, and each idea can have pro/con responses. It's a meritocracy based on votes.
Stack: Django, Django REST, PostgreSQL, React
Content Management System
Supports automatic content cache, without warm-up, optimization of image sizes and minifying of CSS and JavaScript, or page previews.
The content is organized in a tree shape and can be moved around using drag-and-drop. The pages include authentication, and plugins may be inserted in the pages. Any data model may be related with any other model.
The email system is based on templates and integrated with the CMS. The emails sent can collect data such as clicked links and support many other features.
I will be glad to give you a demonstration!
Solvencyii Wire
http://siiwdata.solvencyiiwire.com/Insurance companies provide balances in PDF format. Those are scanned and translated into Excel spreadsheets. And, after human checking, they are imported into a database. From there, many queries are possible in a web UI.
CHEP Aerospace (via Toptal)
CFMC | Qualtrics Surveys (via Toptal)
http://www.qualtrics.comA Portuguese to Portuguese Dictionary in React
http://www.naduvida.com.brStack: Django, Django REST, NGINX, Node.js, React
Ad Server
Controlling campaigns, by client, by time, quantity, and user geolocation. Reports are generated by client, ad campaigns, click rate, etc.
Stack: Python, Django, jQuery, MySQL, Ubuntu, Nginx, DigitalOcean
Flight Vector Tracker
http://flightdutytracker.com/Newsletter Series
The system works based on a timeline around a main event. The timeline may precede and/or succeed the event. Each milestone is associated with an email template and a number of days before or after the main event. On the due date, the email is sent.
The email templates are integrated with user profiles so that message can be personalized.
Stack: Python, Django, jQuery, Cron, Bash, MySQL, Nginx
UprisingTec
http://uprisingtech.com/Various clients, including universities, paid for this information.
Skills
Languages
Python 3, SQL, HTML5, CSS3, JavaScript, HTML, CSS, Python, TypeScript, Python 2, Bash, JavaScript 6
Frameworks
Django, Django REST Framework, Material UI, Vanilla JS
Libraries/APIs
API Development, jQuery, React, REST APIs, MobX, Beautiful Soup, Node.js, Pandas, Twilio API
Tools
NGINX, PyCharm, Figma, Chrome Developer Tools, Cron, GitHub, Pytest, Jenkins, Microsoft Excel, Git, Google Analytics, Supervisord, Excel 2013, Celery
Paradigms
REST, Object-oriented Programming (OOP), Object-relational Mapping (ORM), Design Patterns, MVC Design, HIPAA Compliance, ETL
Platforms
Ubuntu, DigitalOcean, Web, Linux, Firebase, MacOS, Windows, Twilio
Storage
Databases, MySQL, Database Management, Redis, MongoDB, PostgreSQL, Relational Databases, Neo4j, SQLite, Cache
Other
Back-end, APIs, Ubuntu Server, Content Management Systems (CMS), Full-stack, Full-stack Development, Front-end, Web Development, Software, API Integration, Software Development, Audio, CSV, Front-end Development, Web Scraping, Startups, Data Scraping, PWA, Progressive Web Applications (PWA), Data Handling, Health Policy, Trade, Physics, Mathematics, Lab, Reports, Gunicorn, Open Source, ChatGPT, OpenAI GPT-4 API, OpenAI, OpenAI GPT-3 API, DALL-E, OpenAI API, GPT, Chrome Extensions, Algorithms, PDF, Videos
Education
Bachelor of Science Degree in Physics
Fundação Educacional de Bauru - São Paulo, Brasil
Certifications
ChatGPT Prompt Engineering for Developers
DeepLearning.Ai
OpenAI API with Python Bootcamp: ChatGPT API, GPT-4, DALL-E
Udemy
Node.js, Express, MongoDB & More: The Complete Bootcamp 2023
Udemy
OpenAPI: Beginner to Guru
Udemy
HIPAA Privacy & Security for Business Associates
Evolve E-learning Solution
Complete Guide to TensorFlow for Deep Learning
Udemy
The Complete React Native and Redux Course
Udemy
Functional Programming with Python
Udemy
Asynchronous JavaScript
Udemy
Toptal React Academy
Toptal
ES6 JavaScript: The Complete Developer's Guide
Udemy
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