Michael Herold, Developer in Fort Lauderdale, FL, United States
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Michael Herold

Verified Expert  in Engineering

Software Developer

Fort Lauderdale, FL, United States
Toptal Member Since
April 8, 2017

Michael is a talented software engineer with ten years of experience specializing in web app development. He is proficient in JavaScript, Ruby, Python, and Go and has been recognized for delivering clean and maintainable code. With a strong background in client and server architecture, relational and non-relational databases, and REST APIs, Michael has contributed to a diverse range of businesses, from startups to enterprise software companies, and his work has impacted millions of users.


CB Insights
Python, Go, Docker, Amazon Web Services (AWS), APIs, REST, Agile, TypeScript...
Brooklyn Wine Exchange
React, Ruby on Rails (RoR), Heroku, PostgreSQL, Sidekiq, RSpec, Webpack, HTML...
UCSD | University of California San Diego
PostgreSQL, Python, Elasticsearch, Docker, REST




Preferred Environment

Chrome, Git, Visual Studio Code (VS Code), Linux, MacOS

The most amazing...

...thing I've built is a database architecture to ingest and maintain accurate, accessible data for millions of building contractors.

Work Experience

Senior Software Engineer

2021 - 2022
CB Insights
  • Designed an advanced survey system to generate leads between companies and potential investors.
  • Optimized a Python-based spreadsheet application to make column and row management more user-friendly.
  • Built a back-end endpoint to generate data for market profiles, resulting in an increased SEO presence for the company.
Technologies: Python, Go, Docker, Amazon Web Services (AWS), APIs, REST, Agile, TypeScript, Node.js, Elasticsearch, React

Ruby on Rails and React Developer

2020 - 2021
Brooklyn Wine Exchange
  • Worked on a major refactoring of the shopping cart, checkout, and payment codebase, which improved the checkout experience and substantially reduced critical bugs associated with inventory errors, order totals, and credit card verification.
  • Redesigned the product search UI, offering users cascading search filters and sorting features.
  • Contributed to the monthly subscription functionality, handling all UI and back-end management of subscription statuses.
  • Created various new UIs for both the mobile and desktop experience.
  • Built a gift card feature, which included a page to purchase a gift card, the back-end logic to integrate with the financial software that powers the gift cards, and the code to redeem gift cards at checkout.
Technologies: React, Ruby on Rails (RoR), Heroku, PostgreSQL, Sidekiq, RSpec, Webpack, HTML, APIs, REST, CSS, Ruby

Database Engineer

2019 - 2019
UCSD | University of California San Diego
  • Designed and configured an Elasticsearch cluster, determining which data analysis and indexing techniques to use to maximize search performance and usability. Performance was a key issue due to the amount of data.
  • Deployed the Elasticsearch cluster with Docker and Docker Compose, following the best security practices.
  • Ensured that the cluster nodes were distributed on multiple university servers for redundancy and performance.
  • Validated and streamlined data ingestion using Python and PostgreSQL.
  • Configured an interactive Python interface for the university faculty to search and export scientific data using Docker and Python.
  • Created a Python-based data ingestion pipeline to import and index data from many different medical studies.
Technologies: PostgreSQL, Python, Elasticsearch, Docker, REST

Software Engineer

2018 - 2019
  • Worked on a mobile app running on iOS and Android, built with Ionic Cordova. Leveraged Angular, JavaScript (TypeScript), and CSS to develop the code and Xcode and Android Studio to build and test the app.
  • Wrote a Python-based scraper to collect daily gas station prices in the US. I configured the scraper to use Amazon DynamoDB for data storage and AWS Lambda to run the scraper when needed.
  • Integrated a mobile app with the Toyota API to access users' vehicles remotely.
  • Used Google Maps API and WebSockets to track and display real-time vehicle locations, which involved using custom Google Maps layers and pop-ups.
  • Contributed to the development of a large Ruby on Rails API server for a mobile application.
  • Implemented seamless integration with remote command vehicle APIs like Toyota and OnStar using Ruby on Rails to give Yoshi remote access to users' vehicles.
  • Developed extensive unit and integration tests using RSpec, driving a significant increase in testing coverage and promoting a culture of automated testing within the company.
  • Improved Twilio integration to automatically purchase and activate new Twilio phone numbers by area code based on message delivery latency calculations.
Technologies: Amazon Web Services (AWS), PostgreSQL, Angular, Ionic, TypeScript, Ruby on Rails (RoR), Ruby, Python, RSpec, HTML, Sidekiq, APIs, REST, CSS, Agile, React, Web Scraping

Software Developer

2017 - 2018
Element Group
  • Built a platform-as-a-service (PaaS) for companies to sell tokens based on smart contracts on the Ethereum network. The platform provided a checkout flow for investors to purchase tokens with Bitcoin, Ether, or fiat currency.
  • Developed the administrative side of the token sales platform, allowing companies to access investment activity, manage email communications with investors, access analytics, set pricing rules for investor groups, and distribute tokens.
  • Created an onboarding application for customers seeking to use Element Group's brokerage services. The app verifies applicants' identities, collects necessary documents, and integrates with DocuSign to provide a user-friendly experience.
  • Wrote smart contracts in the Solidity programming language, establishing specifications for the Ethereum-based tokens used in our token sales.
  • Implemented automated tests for these smart contracts using the Truffle framework.
  • Built distributed applications (DApps) that use an Ethereum blockchain back end and a client-side JavaScript front end integrated with the Chrome MetaMask plugin, enabling calls to smart contracts.
  • Collaborated with an Agile team with continuous integration and highly automated testing coverage.
  • Worked on numerous front-end features using JavaScript, React, CSS, and HTML.
Technologies: Amazon Web Services (AWS), Solidity, Docker, Node.js, JavaScript, PostgreSQL, Ruby on Rails (RoR), RSpec, HTML, APIs, REST, CSS, Ruby

Software Developer

2017 - 2017
  • Created an online marketplace for Amazon authors to buy and sell email promotions. Two weeks after launch, the platform had already recorded over $10,000 in gross payment volume.
  • Developed, configured, and deployed a Rails 5 application.
  • Integrated various external APIs such as Stripe, Mailchimp, AWeber, and Amazon's Product Advertising API, requiring OAuth and OAuth 2 specifications.
  • Handled all DevOps work, including setting up a Passenger and Nginx server on an AWS Linux Ubuntu box, used Redis and Sidekiq to manage background jobs, and leveraged Amazon's CloudFront CDN to serve assets, prioritizing site performance.
  • Stored and encrypted sensitive user data, adhering to industry best practices for web and data security.
  • Built the front end using JavaScript, React, and CSS and managed and bundled the front-end code using npm and webpack.
Technologies: Stripe API, Amazon Web Services (AWS), Redis, Webpack, React, ECMAScript (ES6), Ruby on Rails (RoR), Ruby, HTML, Sidekiq, APIs, REST, CSS

Software Developer

2014 - 2017
  • Developed with Ruby on Rails, following industry best practices to ensure the creation of readable and maintainable code.
  • Managed MySQL and PostgreSQL databases, building a data ingestion framework, conducting data modeling, and developing query optimization to increase the performance of our web application.
  • Constructed APIs for our single-page applications and APIs to power our data partnerships.
  • Built user interfaces with AngularJS and jQuery that allowed BuildZoom contractors to manage their ongoing projects, communicate with clients, view project histories, and manage photo galleries.
  • Created a matching algorithm encompassing data normalization, stemming, Levenshtein distances, and stop word filtering, which was at the heart of nearly all of our data partnerships with 3rd parties.
  • Wrote performant data-processing scripts in Ruby and Python.
  • Configured and debugged Elasticsearch indices on a full-text search engine to improve the website user search.
  • Implemented Google's machine learning Python module, Scikit-learn, to train a classifier and classify building permit data.
  • Contributed to various front-end features using JavaScript, HTML, and CSS.
  • Worked on an extensive Python scraping app to intelligently collect contractor and building permit data from across the US on an ongoing basis. This also included a data pipeline to sanitize, normalize, and transfer data to PostgreSQL databases.
Technologies: CSS, HTML, JavaScript, Python, PostgreSQL, Ruby on Rails (RoR), Ruby, RSpec, Sidekiq, APIs, REST, AngularJS, React, Web Scraping

Physics Teacher

2012 - 2013
Green Dot Public Schools
  • Helped young minds gain an intuitive sense of the physics of the world around them through lab activities and hands-on learning.
  • Taught physics with algebra, both theory and experiments.
  • Managed the behavioral expectations of more than 20 adolescents.
Technologies: Teaching

Physics Teaching Assistant

2010 - 2012
Auburn University
  • Instructed undergraduate engineering students in the subject of physics.
  • Assisted undergraduate physics students with laboratory assignments.
  • Taught as an assistant in four different physics courses.
Technologies: Fortran


An online marketplace for Amazon authors to buy and sell email promotions. This Ruby on Rails web application leverages Stripe Connect to allow peer-to-peer payments.

Authors integrate their mailing platform API of choice (Mailchimp, AWeber, MailerLite, or ConvertKit) to validate and share their mailing list information. The site saw great user traction and a healthy volume of payments within the first couple of weeks.

Database Model

I modeled phenotype and metabolomics data from worldwide research studies to ingest and normalize data. With this data model, I was able to index this medical data in Elasticsearch and allow research scientists to query it easily.

Solidity Compound Interest Smart Contract

A smart contract explicitly designed for the Ethereum network. The contract offers compound interest on users' investments and compounds the money every second. This cryptocurrency was developed using technologies such as Solidity.


Ruby, JavaScript, Python, CSS, TypeScript, Go, HTML, Fortran, ECMAScript (ES6), Solidity


Ruby on Rails (RoR), Flask, AngularJS, Angular, Django, Ionic


RSpec, Git, Webpack, Xcode, Android Studio, MailerLite


REST, Agile


Visual Studio Code (VS Code), Amazon Web Services (AWS), Heroku, Linux, Docker, Blockchain


PostgreSQL, Elasticsearch, Redis


APIs, Web Scraping, Hardware Design, Numerical Programming, Physics


React, Sidekiq, Node.js, Stripe API

Industry Expertise


2010 - 2012

Master's Degree in Physics

Auburn University - Auburn, AL, USA

2004 - 2008

Bachelor of Science Degree in Electrical Engineering

University of Southern California - Los Angeles, CA, USA


Toptal Blockchain Academy


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