David Rozenberg, Developer in New York, NY, United States
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David Rozenberg

Verified Expert  in Engineering

API Developer

New York, NY, United States
Toptal Member Since
August 12, 2021

David is a back-end-leaning full-stack software engineer with a breadth of experience in different industries, including the clinical trials space, real estate tech, and defense. David enjoys designing and building applications and APIs, architecting systems, and learning new skills.


Java, JavaScript, Python, Scala, Amazon Web Services (AWS), Data Pipelines
Medidata Solutions
Ruby on Rails (RoR), JavaScript, React, Amazon Web Services (AWS), PostgreSQL...




Preferred Environment

Ruby on Rails (RoR), React, Python, Amazon Web Services (AWS), CSS, JavaScript, Next.js

The most amazing...

...thing I've developed is Roomeze, an app to help people find multi-bedroom apartments and roommates, helping put thousands of people into apartments in NYC.

Work Experience

Senior Software Engineer

2020 - PRESENT
  • Developed a quick look experience allowing customers to quickly evaluate items and add them to cart without navigating away from the shopping experience.
  • Built a scalable and maintainable data pipeline to generate different recommendation strategies for customers.
  • Oversaw the upgrade of various systems to Amazon Web Services (AWS) from legacy technologies.
Technologies: Java, JavaScript, Python, Scala, Amazon Web Services (AWS), Data Pipelines

Senior Applications Engineer

2015 - 2020
Medidata Solutions
  • Served as a feature lead developing a new statistical analysis tool for clinical trials. Designed APIs, front end, and back end to monitor key risk indicators.
  • Developed applications and automated tests on microservice architecture handling authorization, authentication, core objects, and administrative UI.
  • Selected for a high-performing team to implement ETL process migrating millions of legacy records into the new Medidata platform.
Technologies: Ruby on Rails (RoR), JavaScript, React, Amazon Web Services (AWS), PostgreSQL, SQL, APIs, Graph Databases


Built a real estate web application from the ground up, allowing users to search for rooms, roommates, and apply for apartments, placing more than 2,000 people into NYC apartments and supporting traffic of around 20,000 users per week.


JavaScript, Python, SQL, Java, Scala, CSS


Ruby on Rails (RoR), Next.js




Amazon Web Services (AWS)


PostgreSQL, Graph Databases, Data Pipelines


Engineering, Software Engineering, APIs, Biomedical Skills



2005 - 2009

Bachelor's Degree in Biomedical Engineering

Boston University - Boston, MA, USA