Scroll To View More
Michael Herold, Python Developer in San Francisco, CA, United States
Michael Herold

Python Developer in San Francisco, CA, United States

Member since February 2, 2016
Mike is a talented software engineer with an expertise in web applications. He is fluent in JavaScript, Ruby, and Python and takes pride in writing clean, maintainable code. Mike is based in San Francisco with years of experience in the startup scene. Development-wise, Mike has focused on both client and server architecture and his strengths include relational and non-relational databases and REST APIs.
Michael is now available for hire


  • Element Group
    Ruby on Rails, PostgreSQL, JavaScript, Node.js, AWS, Docker, Web3.js, Solidity
  • BookClicker
    Ruby on Rails, MySQL, ES6, React, Webpack, Redis, Nginx...
  • BuildZoom
    Ruby, Rails, PostgreSQL, Python, JavaScript, HTML, CSS


  • Ruby on Rails (RoR), 5 years
  • PostgreSQL, 4 years
  • Linux, 3 years
  • Elasticsearch, 2 years
  • React, 2 years
  • Python, 2 years
  • Node.js, 1 year
  • Docker, 1 year
San Francisco, CA, United States



Preferred Environment

Mac or Linux, Emacs, Git, Chrome

The most amazing...

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


  • Software Developer

    2017 - 2018
    Element Group
    • Built a token sale platform (platform as a service) for companies to sell tokens based on smart contracts on the Ethereum blockchain network. This platform includes a customizable checkout flow for investors to purchase tokens with Bitcoin, Ether, or fiat currency. This platform can also be run on Bitcoin and Ethereum test networks for quality assurance.
    • Developed the admin side of the token sale platform for companies to see the investment activity, manage email communications with investors, view analytics, set pricing rules for investor groups, distribute tokens, and more.
    • Constructed an onboarding application for customers applying to use Element Group's brokerage services. This application verifies applicants' identities, collects required documents, and integrates with DocuSign for a pleasant user experience. This is a Ruby on Rails application deployed with Docker to AWS Fargate.
    • Wrote smart contracts in the Solidity programming language which established specifications for the Ethereum-based tokens used in our token sales.
    • Developed automated tests for these smart contracts using the Truffle framework.
    • Built distributed applications (dApps) which use the Ethereum blockchain as the back-end, and client-side JavaScript as the front-end. The JavaScript integrates with the Chrome Metamask plugin to make calls to smart contracts. One of these applications, for example, allows token managers to access the security features of their tokens, such as whitelisting certain accounts to be able to send and receive tokens.
    • Worked within an Agile team, with continuous integration and high automated testing coverage.
    Technologies: Ruby on Rails, PostgreSQL, JavaScript, Node.js, AWS, Docker, Web3.js, Solidity
  • Freelance Software Developer

    2017 - 2017
    • Created an online marketplace for Amazon authors to buy and sell email promotions. 2 weeks after its launch the platform had already seen over $10,000 in gross volume of payments.
    • Developed, configured, and deployed a Rails 5 application.
    • Integrated various external APIs such as Stripe, MailChimp, AWeber, and Amazon's Product Advertising API. This API work included OAuth and OAuth 2 specifications.
    • Handled all of the DevOps work; configured a Passenger and Nginx server on an AWS Linux Ubuntu box. Redis and Sidekiq were used to manage background jobs. Assets were served through Amazon's CDN CloudFront and site performance was considered heavily.
    • Securely stored and encrypted sensitive user data. Followed best practices for web and data security.
    • Developed the front-end using JavaScript (ES6) and React. The JavaScript code was bundled with Webpack and dependencies were managed with the Node Package Manager (NPM).
    Technologies: Ruby on Rails, MySQL, ES6, React, Webpack, Redis, Nginx, Amazon Web Services (AWS), Stripe API
  • Software Developer

    2014 - 2017
    • Developed with Ruby on Rails and followed best practices to write readable, maintainable code.
    • Managed MySQL and PostgreSQL databases—building out a data ingestion framework, data modeling, and developing a query optimization to increase the performance of our web application.
    • Constructed APIs for our single-page applications as well as APIs to power our data partnerships.
    • Built user interfaces which allowed BuildZoom contractors to manage their current projects, communicate with clients, visualize project histories, and manage photo galleries (with AngularJS and jQuery).
    • Developed a matching algorithm involving data normalization, stemming, Levenshtein distances, and stop word filtering which has been 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 (a full-text search engine) indices to improve user search on the site.
    • Implemented Google's machine learning Python module (Scikit-learn) to train a classifier and classify building permit data.
    Technologies: Ruby, Rails, PostgreSQL, Python, JavaScript, HTML, CSS
  • 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.
    Technologies: Teaching
  • Physics Teaching Assistant

    2010 - 2012
    Auburn University
    • Gave physics instruction to undergraduate engineering students.
    • Assisted students with laboratory assignments.
    • Taught as an assistant for four different physics courses.
    Technologies: Fortran, MATLAB


  • BookClicker (Development)

    An online marketplace for Amazon authors to buy and sell email promotions. This is a Ruby on Rails web application that leverages Stripe Connect to allow peer-to-peer payments. Authors integrate with 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 weeks.


  • Languages

    Ruby, JavaScript, Python, Solidity
  • Frameworks

    Ruby on Rails (RoR), Flask, AngularJS, Django
  • Paradigms

    REST, Agile
  • Storage

    MySQL, PostgreSQL, Elasticsearch, Redis
  • Other

  • Libraries/APIs

    React, Sidekiq, Gmail API, Stripe API, Node.js, Web3.js
  • Platforms

    Linux, Blockchain, Docker
  • Tools



  • Master's degree in Physics
    2010 - 2012
    Auburn University - Auburn, AL, USA
  • Bachelor of Science degree in Electrical Engineering
    2004 - 2008
    University of Southern California - Los Angeles, CA, USA
  • Toptal Blockchain Academy
    JUNE 2018 - PRESENT
I really like this profile
Share it with others