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CZI Technology

The Chan Zuckerberg Initiative (CZI) leverages technology, community-driven solutions and collaboration to help solve some of today’s toughest issues — from eradicating disease and improving education, to addressing the needs of our local communities. Our mission is to build a more inclusive, just and healthy future for everyone, and we decided to get an inside look into what products CZI’s employees are building to help achieve this goal.

Shane Skikne is a Senior Software Engineer at CZI partnering with educators and researchers to build products within our Education Initiative. We sat down (virtually!) …


The Chan Zuckerberg Initiative (CZI) leverages technology, community-driven solutions and collaboration to help solve some of today’s toughest issues — from eradicating disease and improving education, to addressing the needs of our local communities. Our mission is to build a more inclusive, just and healthy future for everyone, and we decided to get an inside look into what products CZI’s employees are building to help achieve this goal.

Leslie Chang is an Engineering Lead at CZI working on the Frontend Infrastructure of products our Education Initiative is building in partnership with educators and researchers. We sat down (virtually!) …


At the Chan Zuckerberg Initiative (CZI), we use RedisMemo to improve the performance and reliability of our products, Summit Learning and Along.

https://github.com/chanzuckerberg/redis-memo

RedisMemo is an application-level caching system for Ruby programs. It can be used to cache database queries (with built-in support for ActiveRecord), third-party API calls, pure functions, or any combination thereof.

app/models/user.rb

With RedisMemo, to cache all the select-by-id queries on the users table, only two lines of code are needed in the User model (details in section 3.2).

In the Rails console, the author method on the post object loads data from Redis instead of the database:


Accessibility is important to the Chan Zuckerberg Initiative (CZI), because we envision a country where every student enters adulthood prepared to reach their full potential. This vision isn’t possible if students or teachers are excluded because of a disability.

To support equity and inclusion, we recently started to test our React components for accessibility. Doing so provides faster feedback to engineers, and helps prevent many accessibility problems from getting to our users.

To test for accessibility, we

  1. Write React component examples in component story format.
  2. Use axe-storybook-testing to test these stories for accessibility.
  3. Run the tests in our continuous integration…


At CZI, we’ve adopted Sorbet, a fast and powerful static type-checking tool for Ruby. In our previous post, we talked about the technical challenges of adopting Sorbet in a Rails codebase, which led us to develop the sorbet-rails gem. After a year of using Sorbet, we have made significant progress covering our system with types. Currently, we have reached 92% file-level typed coverage and 75% callsite-level typed coverage. Most importantly, Sorbet is now integrated into every engineer’s development flow. In this post, we’ll go through our phases of adopting Sorbet and the challenges and the lessons we learned along…


The Chan Zuckerberg Initiative (CZI) leverages technology, community-driven solutions, and collaboration to accelerate progress in Education, Justice & Opportunity, and Science. CZI’s Infrastructure Engineering team is responsible for building shared infrastructure that serves the philanthropy’s efforts in these core areas. Though each team is working toward specific goals, they share many common technical challenges: they all handle sensitive data, manage compute resources, and onboard new engineers often.

We manage our cloud infrastructure on AWS, so we need a secure way for engineers, data scientists, and I.T. admins to get work done in AWS. …


IDseq is a real-time pathogen detection dashboard that helps prevent outbreaks around the world. The IDseq team is building a pipeline to identify pathogens in metagenomic sequencing data, and needed to deal with huge huge files in the AWS Simple Storage Service (S3). However, when we used existing tools, we ran into several problems, including:

  • Slowness: downloading such large objects took way too long, even on high tier machines
  • Archive inefficiency: un-archiving directories of large files took even longer than the download
  • Integrity check: S3 built-in integrity checks don’t run for such large objects
  • Metadata not transferring: metadata won’t transfer…


Timmy Huang is a Staff Software Engineer at the Chan Zuckerberg Initiative. Timmy works as a frontend developer on Meta, a research discovery tool that uses machine learning to provide a faster way to understand and explore science. I was curious to learn more about Timmy and the adventures that eventually led him to CZI!

Timmy, thank you so much for agreeing to be interviewed! Can you tell me a little bit about where you’re from and how you came to CZI?

Thank you for having me, Arathi! 🤩

A little bit about myself:

🐣🇹🇼➡ 👶🤠🇺🇸➡ 👦🏻📚🇹🇼➡👨‍🎓📽️📀🇺🇸➡👨‍💻🗽💻➡👰🏻🤵💍➡😍🖖💜🌈

Translation: I was born in Taiwan, then we moved to Texas when I was one year old so my dad could get his PhD. Then we went back to Taiwan…


At CZI, we developed a personalized learning application, the Summit Learning platform, using the Ruby on Rails framework. In the early days, Rails enabled us to build out the platform quickly. However, now that we have 30+ engineers and 2,500+ files of Ruby code written over 6 years, we’ve found it harder to iterate. To help us move faster together, we decided to adopt Sorbet, a fast and powerful static type-checking tool for Ruby.

In this post series, we’d like to share our journey adopting Sorbet: the challenges and the lessons we learned from tackling those challenges. By reading these…


The only way technology can solve the world’s most pressing problems, like improving education, managing disease and reforming the criminal justice system, is through radical collaboration between technologists and those working on the frontlines of these very issues. For many software engineers, building products toward our missions in Science, Education, and Justice & Opportunity is quite different from what they’ve worked on before. We sat down with software engineer Arathi Mani from the science team to learn more about her journey to the Chan Zuckerberg Initiative (CZI).

At NeurIPS 2019

Arathi, what was a pivotal moment for you in your career?

As far…

CZI Technology

The Technology team at Chan Zuckerberg Initiative

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