Mauro Leonardo Sabatelli de Moura, Developer in New York, NY, United States
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Mauro Leonardo Sabatelli de Moura

Verified Expert  in Engineering

Software Developer

New York, NY, United States
Toptal Member Since
May 16, 2022

Mauro is a skilled entrepreneur and software engineer with over five years of experience developing back-end applications and integrations. Mauro spearheaded the creation of a wealth management back-office system using Node.js and founded a tech consultancy firm to help companies modernize their processes.


JavaScript, AutoML, Google Cloud Natural Language, Node.js, Amazon S3 (AWS S3)...
Loyall Investimentos Ltda
Node.js, TypeScript, MongoDB, MySQL, Excel VBA, Agile Sprints, Scrum, REST...
Web Scraping, Scraping, Node.js, PostgreSQL, Data Scraping, Axios, CheerioJS...




Preferred Environment

Visual Studio Code (VS Code), MongoDB, MySQL, JavaScript, Node.js, TypeScript, OpenAI GPT-4 API, Back-end Architecture, React, React Native

The most amazing...

...project I've created is an AI chatbot with domain-specific knowledge to extract data, answer queries, interact with users, and generate analysis for companies.

Work Experience


2021 - PRESENT
  • Developed a web scraping service that retrieves unstructured data from public sources using Node.js and stores it as structured data with MySQL so that it can be properly used by non-technical managers, using REST API, Google Sheets, Excel, and Power BI.
  • Helped an old-school company modernize its operations by structuring workflows with Google Sheets and GAS user-friendly interface to monitor information from non-technical employees to managers with an organized AWS RDS database.
  • Developed a call center tool that allows agents to quickly simulate their price quotes according to their customers' needs by retrieving data from REST API with Node.js and Express.js integrated with a MySQL database.
Technologies: JavaScript, AutoML, Google Cloud Natural Language, Node.js, Amazon S3 (AWS S3), Amazon RDS, REST, Sequelize, SQL, Visual Studio Code (VS Code), GitHub,, APIs, Back-end Development, JSON, ECMAScript (ES6), Clean Code, SOLID Principles, REST APIs, API Integration, Databases, ETL, Excel Expert, Express.js, Excel 365, Automation, Web Applications, Data Scraping, Back-end, Integration, Scraping, Excel Macros, Git, Microsoft Excel, MERN Stack, Google Apps, JSON REST APIs, API Design, Software Analysis, API Connectors, Architecture, Business Architecture, Enterprise Architecture, Back-end Architecture, Amazon Web Services (AWS), WebSockets, Robotic Process Automation (RPA), Artificial Intelligence (AI)

Partner, Operations and Technology

2017 - PRESENT
Loyall Investimentos Ltda
  • Led the project and development of the company's operating system to automate and integrate portfolio management from operations to customer reporting. The system back end was based on Node.js with MongoDB+MySQL databases and Discord (communication).
  • Transformed an outdated Excel/email based system into a modern back-end system with REST APIs including Node.js+Express.js, queues (RabbitMQ), CronJobs (Agendash), and modern tools from the GCP such as databases, AutoML, Maps, Apps Script, and GCF.
  • Created and maintained the Data Lake used by the company to store financial market registry and end-of-day information such as prices and volumes by extracting data from various structured data sources or web scraping.
Technologies: Node.js, TypeScript, MongoDB, MySQL, Excel VBA, Agile Sprints, Scrum, REST, Sequelize, SQL, Visual Studio Code (VS Code), JavaScript, GitHub, GitLab, Robotic Process Automation (RPA), APIs, Docker, Back-end Development, Google Cloud Platform (GCP), JSON, Financial Data, XML, ECMAScript (ES6), Clean Code, SOLID Principles, Webhooks, API Documentation, REST APIs, API Integration, Databases, ETL, Excel Expert, Express.js, Excel 365, Automation, Web Applications, Data Scraping, Selenium, Back-end, Integration, Scraping, Excel Macros, Git, NoSQL, Discord Bots, Puppeteer, Google Sheets, JSON REST APIs, API Design, Jest, API Connectors, Architecture, Business Architecture, Enterprise Architecture, Algorithms, Back-end Architecture, Serverless, WebSockets

Node.js Scraping Expert

2023 - 2023
  • Developed a web scrapper to fetch market information in a programmatic manner using TypeScript with Express.js writing to a PostgreSQL database.
  • Designed and orchestrated the workflow to execute multiple fetching routines in a programmatic and scalable way using queued jobs with BullMQ (Redis).
  • Specified layers to control the usage of third-party APIs, avoiding overloading or being blocked by external services.
Technologies: Web Scraping, Scraping, Node.js, PostgreSQL, Data Scraping, Axios, CheerioJS, Puppeteer, Redis, Redis Queue, TypeScript, Docker, Docker Compose, JSON, HTML, jQuery, XML, API Connectors, Algorithms, Back-end Architecture, WebSockets, Robotic Process Automation (RPA)

Expert Developer

2022 - 2022
Declan Wesley Whitmyer
  • Structured the user-story workflow for the project, then properly designed a suitable database to support the data exchange needs.
  • Developed the base infrastructure to minimally integrate the client's app to three external services, according to their API limitations, and validate the feasibility of their app.
  • Prepared all the user creation, validation, and authentication process and minimum integration with the external services providers.
  • Spotted the missing points that required external accomplishments regarding the business to enable further development of the application's back end.
Technologies: APIs, JSON, REST, REST APIs, JSON REST APIs, API Design, API Documentation, JavaScript, Software Analysis, API Connectors, Algorithms, Test-driven Development (TDD), Back-end Architecture, Robotic Process Automation (RPA)

Founder | Developer | Manager

2021 - 2021
Loja Do Presente
  • Developed a proprietary dropshipping website that connects AliExpress sellers with Brazilian customers through a 100% integrated workflow to purchase items from AliExpress and ship them directly to the customer's address through the Shopify platform.
  • Integrated the website with Facebook to target ads to the appropriate customer profiles using Facebook Pixel. Also, integrated the payment methods (Yampi+MercadoLibre) into the checkout page.
  • Developed post-sales automations using Shopify automation tools to notify customers of shipping information and managed marketing strategies like offering discount coupons for detailed reviews, referral offers, etc.
Technologies: Facebook Ads, Facebook Pixel, Facebook API, Shopify, Shopify API, HTML, CSS, HTML5, REST APIs, API Integration, Databases, ETL, Excel 365, Automation, Web Applications, Excel Macros, Git, Microsoft Excel, Google Sheets, JSON REST APIs, API Connectors, Business Architecture, Back-end Architecture, Amazon Web Services (AWS), WebSockets, Robotic Process Automation (RPA)

Investment Portfolios Managing App

I was the back-end developer of a web application that can do all the calculations needed to manage an investment fund.

It calculates portfolio holdings daily, based on previous and daily operations, performing asset and liability calculations. It automatically integrates with brokerage and custody accounts to retrieve all necessary information on day-to-day operations. It reconciles all data with fund administrators and other third parties involved in managing mutual funds, ETFs, and hedge funds.

The market data comes entirely from our internal data repository, updated daily from myriad data sources such as the Brazilian Stock Exchange (B3), Brazilian regulators (CVM, Anbima), and many other financial institutions.
The application also creates customized reports for back-office staff, fund managers, and fund clients. It also enabled further Power BI and Excel integrations by mapping its no-SQL database to an SQL database. It also communicates and alerts users using Discord API

Aside from the technical benefits, the company could eliminate $5+ thousand per month in external software licensing expenses by implementing a proprietary system.

Financial Market Data ETL and Repository

A data repository of curated market information that can be used by financial portfolio managers and portfolio management systems. It extracts and curates asset information from several official data feeders and performs all necessary calculations, such as asset returns, volatility, and volumes, based on end-of-day prices, payouts, corporate actions, and all necessary information.

The application also analyses and loads macroeconomic data, company fundamentals from quarterly reports, and other specific information to allow users to extract data for their business intelligence reports.

The application has an automatic checking routine to detect missing or doubtful information based on many predefined algorithms to ensure the completeness and meaningfulness of the database.

Healthcare Insurance Brokers Call Center Pricing App

I developed the back end of a call center app that kept a SQL database storing up-to-date pricing quotations for thousands of health insurance plans available in Brazil for small and medium businesses.

Call center agents could quickly determine the best price quotes for each customer by submitting the information required by the system through a REST API and then simulating the quotes according to the customer's needs.

The application stored the information about the simulations and the agents, in compliance with privacy regulations, LGPD and GDPR, for further analysis by the managers to increase the effectiveness of the sales team.

An E-Commerce platform based on dropshipping connects AliExpress sellers to Brazilian customers using the Shopify Platform. Facebook Ads were integrated into our website through Facebook Pixel. I have developed all the automations to properly create purchase orders to Ali Express and deliver the product to the customer's address using DSERS + Oberlo tools. The checkout+payment methods were performed with Yampi+MercadoLibre tools. Furthermore, I monitored the shipping status and integrated it into our website using 17Track API.

Newsletter Auto Analyst with ML

Developed an ML-driven application to read and parse structured information from a selection of approximately 50 email newsletters and RSS feeds using IBM Watson NLU. Keywords and sentiments were extracted from each message and a post-processing algorithm was able to obtain the most relevant topics and their sentiments from a given time period. The structured results were presented in a MySQL database that provided information for asset fund managers as well as for the company's weekly newsletter.

Monday/Pipefy Workflow Integration

An automation app to automate and unify a workflow between the Pipefy and Monday apps using their REST/GraphQL APIs to integrate both systems into a central MySQL database using Node.js. Routines were run to synchronize data, and several automated scripts were triggered to create, upload, and download files across both systems and a data server. A dedicated relational database was developed to store and compute data, control and monitor script execution, and allow company managers to create custom reports to monitor KPIs and other custom indicators.

Timesheet Automation with Google Sheets

I've developed a complete Google Sheet automation using Google Apps Script to help users fetch data from external sources, validate input information, automate tasks and generate reports to further integrate with third-party apps.

It was created in a manner that also could be run in pre-scheduled routines and have access conditions to authorize users to perform controlled actions properly.

OpenAI QA/Analyst Chatbot

The AI Analyst Chatbot is an innovative, intelligent solution that provides comprehensive analytical support for businesses across various industries. Utilizing OpenAI API and the LangChain toolkit, this chatbot is adept at extracting specific data, answering complex questions, interacting with users, and generating in-depth analysis on relevant industry issues.

Developed in TypeScript with the NestJS framework, the chatbot is integrated with Discord to enable seamless user interaction, facilitating almost real-time communication and collaboration.
To manage and retrieve documents, the chatbot employs Pinecone, a vector database, allowing for efficient storage and retrieval of relevant information. Leveraging its intelligent document selection capabilities, the chatbot can identify pertinent documents and craft informed responses based on the user's request or query context.

This project allows companies to have improved decision-making through data-driven insights, reduced response time to critical inquiries, and enhanced overall operational efficiency.
2015 - 2017

Master's Degree in Mechanical Engineering

The Polytechnic University of Milan - Milan, Italy

2012 - 2017

Bachelor's Degree in Mechanical Engineering

Polytechnic School of the University of São Paulo - São Paulo, Brazil


Node.js, REST APIs, Puppeteer, Google Apps, Gmail API, jQuery, Facebook API, Shopify API, CheerioJS, Redis Queue, React


Microsoft Excel, Google Sheets, Sequelize, Microsoft Access, GitHub, GitLab, AutoML, IBM Watson, Facebook Pixel, Git, Prisma, Docker Compose


Express.js, NestJS, Selenium, Jest, React Native


JavaScript, Excel VBA, TypeScript, SQL, ECMAScript (ES6), Visual Basic for Applications (VBA), Visual Basic, XML, Google Apps Script, HTML, CSS, HTML5, GraphQL


REST, ETL, Automation, Back-end Architecture, Clean Code, Object-relational Mapping (ORM), Scrum, MEAN Stack, Test-driven Development (TDD)


MySQL, JSON, MongoDB, NoSQL, PostgreSQL, Amazon S3 (AWS S3), Google Cloud, Databases, Redis


Visual Studio Code (VS Code), Amazon Web Services (AWS), Docker, Google Cloud Platform (GCP), Shopify


Robotic Process Automation (RPA), Web Scraping, APIs, Back-end Development, Financial Data, API Integration, Excel Expert, Excel 365, Data Scraping, Back-end, Integration, Scraping, Excel Macros, JSON REST APIs, API Design, API Connectors, SOLID Principles, Web Applications, MERN Stack, Architecture, Business Architecture, Enterprise Architecture, Serverless, WebSockets, Artificial Intelligence (AI), Numerical Methods, Controlling, Google Cloud Natural Language, Amazon RDS,, Agile Sprints, Natural Language Understanding (NLU), Google Cloud Functions, Discord, Facebook Ads, Facebook, Webhooks, API Documentation, Discord Bots, MEVN Stack, Software Analysis, Axios, OpenAI GPT-3 API, OpenAI GPT-4 API, Vector Data, LangChain, Algorithms

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