Daryl Marco, Developer in Walnut Creek, CA, United States
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Daryl Marco

Verified Expert  in Engineering

Software Developer

Walnut Creek, CA, United States
Toptal Member Since
October 6, 2020

Daryl is a software developer with a passion for learning new technologies. He deployed a photo carousel microservice for an online store's product page whose database contained over ten million products with 22 million product images. He strives to create highly efficient, readable, and reusable code. Daryl has delivered projects using React, Redux, Node.js, Express, and various relational and non-relational databases.


Welltrust Medical Group
CSS, MySQL, Node.js, React, HTML5, JavaScript, TypeScript, Cypress, Material UI...
Kin Health Inc (dba. Songbird Therapy).
HTML, CSS, JavaScript, Webflow, Zapier, Greenhouse, Amplitude, AWS Lambda
JavaScript, React, Bootstrap 4, Azure, VictoryChart, GitHub, Chart.js, HTML




Preferred Environment

JavaScript, CSS, HTML5, MongoDB, Redux, React, Node.js, TypeScript, Cypress, MySQL

The most amazing...

...project I've recently developed is an audio mixing contest website for audio mixing engineers to hone their skills and share their methods.

Work Experience

Full-stack Software Engineer

2020 - PRESENT
Welltrust Medical Group
  • Refactored a patient-facing web application from JavaScript to TypeScript.
  • Instituted end-to-end testing of customer and healthcare provider-facing sites using Cypress.io.
  • Created new APIs to integrate Amazon S3 storage for storing documents to share with healthcare providers.
  • Worked on the database and back-end design changes for creating a patient portal application.
Technologies: CSS, MySQL, Node.js, React, HTML5, JavaScript, TypeScript, Cypress, Material UI, Tailwind CSS, Pug, Express.js, MySQLdb

Web Developer for Custom Web Applications

2022 - 2022
Kin Health Inc (dba. Songbird Therapy).
  • Developed analytics tools using Amplitude to allow linking of marketing efforts to the flow of users at an individual level.
  • Created customized signup forms for new users and employee prospects to replace third-party forms.
  • Linked several services using Zapier and AWS Lambda functions.
  • Improved page load speeds by approximately 50% for the homepage.
Technologies: HTML, CSS, JavaScript, Webflow, Zapier, Greenhouse, Amplitude, AWS Lambda

Senior Front-end Developer

2020 - 2021
  • Collaborated with the founder of a DevOps startup to plan the user experience for the MVP of their product.
  • Developed a React web application for managing server resources with a login system, a central dashboard, a tree structure for browsing resources, search capabilities, and chart views for resources.
  • Created an animated chart to show potential customers the savings possibilities through using the service.
Technologies: JavaScript, React, Bootstrap 4, Azure, VictoryChart, GitHub, Chart.js, HTML


2013 - 2020
Daryl Marco Consulting
  • Built reporting tools for a multiphase CHI health survey to inform participants of results.
  • Created a website for the publisher of English as a second language and other language teaching tools.
  • Created website templates for health care providers.
Technologies: HTML5, JavaScript, Reporting

Marketing Manager

2013 - 2013
Active Interest Media
  • Refined an email billing system for publications including Yoga Journal and Backpacker & Climbing, increasing efficiency by 28%.
  • Created new A/B testing guidelines for holiday gift subscription marketing campaigns.
  • Forecast promotional inventory usage and negotiated contracts for creating new promotional publications.
Technologies: A/B Testing, SQL

Circulation Director

2004 - 2013
Homestyles Media
  • Increased the profitability of direct mail campaign results by over 160% by A/B testing price and package.
  • Accelerated the growth rate of online orders by over 50% by leading the redesign of our online ordering system.
  • Managed subscriber billing, renewal, and marketing with an SQL database.
Technologies: A/B Testing, SQL, HTML

reaMIXed Mixing Contest

I designed this site as a new place for audio mixing engineers to hone their skills and share their methods. The application is built with a React front end, Node.js back end with a MongoDB Atlas database, and Redux for state management. Serverless hosting is handled via Google Cloud Run using Docker for deployment.

SofaWorks Review/Product Info Sections

I worked as part of an agile remote team to develop an online furniture retailer's product page. I created the review and product details sections and developed a proxy to deploy the other microservices. I used Styled Components for the animations and MySQL to handle the data. Microservices and proxy were deployed to Amazon Elastic Container Service.

Craftworkery: Microservice Deployment

For this project, I deployed a photo carousel microservice for the product page of an online store selling bespoke products as part of a distributed remote team using Agile practices with daily stand-ups.

The PostgreSQL photo database contained over ten million products with 22 million product images. This was deployed to AWS Elastic Containers with round-robin load balancing to improve the response times under heavier loads.
1992 - 1998

Bachelor of Science Degree in Economics (Concentration in Marketing)

The Wharton School, University of Pennsylvania - Philadelphia, Pennsylvania, USA


AWS Certified Cloud Practitioner

Amazon Web Services


Software Development

Hack Reactor


Data Science Certification

University of California at Berkeley Extension Program


React, Node.js, API Development, REST APIs, Google AdWords, Chart.js, Google Maps API


Sequelize, Webpack, GitHub, Zapier, Greenhouse


JavaScript, HTML5, CSS, SQL, HTML, Python, SAS, TypeScript, Pug


Express.js, Redux, Material UI, Serverless Framework, Cypress, Tailwind CSS


MongoDB, MySQL, PostgreSQL, Google Cloud, MySQLdb

Industry Expertise

Marketing, Web Design


Test-driven Development (TDD), Microservices Architecture, Data Science


Docker, Firebase, Amazon Web Services (AWS), Azure, Webflow, AWS Lambda


A/B Testing, Full-stack, APIs, Marketing Research & Analysis, Styled-components, Gatsby, Bootstrap 4, VictoryChart, Amplitude, Reporting

Collaboration That Works

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