Justin Barnett, Developer in New York, NY, United States
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Justin Barnett

Verified Expert  in Engineering

Software Developer

New York, NY, United States
Toptal Member Since
March 3, 2022

Justin is a software engineer specializing in the back end and infrastructure. His most proficient languages are Python, Java, React, and JavaScript, and he has worked at big tech companies such as Amazon, Uber, and VMware. As a long-term strategic thinker, Justin focuses on software development at all stages.



Preferred Environment

MacOS, IntelliJ IDEA

The most amazing...

...thing I've made is an algorithmic trading bot that monitors market fluctuations and makes trading decisions.

Work Experience

Software Engineer

2022 - PRESENT
  • Implemented horizontal data access compliance for Google Monarch. Added data auditing to data fields and restricted access to Google Cloud Platform customer data. Developed a parser to identify and extract personal customer info from requests.
  • Wrote technical approach to identify changes affecting build targets through transitive dependencies updates. Implemented a technical approach to create an audit trail for building target changes.
  • Created new alerts to monitor failures and latency spikes in the rollout plugin.
  • Provided mentorship for new team members. Contributed to customer support OKR by modifying and onboarding our team to an automated survey sender tool created by a different team written in Go.
Technologies: C++, Python 3

Software Engineering Consultant

2021 - 2022
Interlace Ventures
  • Iterated on investment pipeline written in Python and migrated data streams to work with new versions.
  • Created tooling to automate permissions to financial data, allowing fine-grain control of company data. Made better data checks to improve the quality of the firm’s database.
  • Converted the startup data structure from a siloed data structure to a graph data structure and increased investor efficiency by enabling faster research.
Technologies: Python, Django, Webflow

Software Development Engineer

2020 - 2022
  • Contributed to Sonata, a platform that ingested hundreds of different data providers across Amazon, enabling marketers to create strategies for showing content that fed data into a content pipeline. Supported over 3,000 different configurations.
  • Led the automating strategy migration so that internal strategies could be created and managed by external marketers, which led to the completion of an initiative that will bring in 100 million in profit for 2021-2023.
  • Provided direct support to the customers and worked with the product teams to create new features for automating marketing processes and increasing efficiency.
Technologies: Java, React, Python


2017 - 2020
Delta X Technology LLC
  • Pursued and launched various entrepreneurial endeavors, such as creating a brand of generic vacuum batteries on Amazon 3P. Imported and sold multiple products, including electric scooter chargers and parts.
  • Acted as a contractor for various seed-stage companies; clients included Hairdoo and Blunt Boxes.
  • Relaunched the first version of the Hairdoo iOS app. Built new features, such as new user onboarding flow, urgency timers, rebooking flow, rebooking from past appointments, and referring a friend.
  • Built the first version of a web ordering portal for a cannabis dispensary in Southern California. Built web ordering flow, handled payments on Stripe, and used Twilio for text messaging.
Technologies: Python, PHP

Software Engineering Intern

2016 - 2016
  • Created China Toggle in Objective-C to show off new pricing in UberPool 2.0. Increased adoption by 0.4%.
  • Engineered Give 1 Get 1 microservice using Go and increased the sharing by 0.1%.
  • Created the accessibility features for the Uber iOS app.
Technologies: Go, Objective-C

Software Engineering Intern

2015 - 2015
  • Developed an automated VM monitoring solution using Nagios and internal APIs.
  • Automated creation of host CFG files by developing Python scripts and leveraging Presto APIs and other internal tools.
  • Created an automated deployment solution using Puppet to enable VM monitoring solution remote deployment.
Technologies: Ruby, Python


DailyStockMarketData.com is a platform that delivers daily stock market data in a convenient CSV. It provides new data every day at about 4:30 pm EST on trading days and offers the subscription feature. The platform can be used to backtest the customer's trading strategies and perform market research.


SparkVid is a video transcription tool that helps users quickly skim video hours.

I got an idea for this tool during COVID-19 after watching hours of videos on meetings and lectures, so I created SparkVid to skim those videos and save users time and energy.
2013 - 2017

Bachelor's Degree in Computer Engineering

University of Illinois at Urbana Champaign - Champaign, IL, USA




IntelliJ IDEA


Amazon Web Services (AWS), MacOS, Webflow




Java, Python, C++, PHP, Solidity, Go, Ruby, Objective-C, Python 3


PostgreSQL, Redis

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