# William Schwarzenbach

> Software engineer

Location: San Francisco, California, United States
Profile: https://flows.cv/williamschwarzenbach

willschwa.com

## Work Experience
### Engineer @ Sierra
Jan 2024 – Present | San Francisco, California, United States

### Staff Software Engineer @ Cash App
Jan 2021 – Jan 2024 | San Francisco, California, United States
Joined the Money Management Team to build consumer financial products.

* Launched Hermes, a notification service that processes thousands of transactions per second, delivering notifications for 50MM customers.
* Coordinated engineers across 4 teams to launch Paychecks, which allows customers to manage and allocate their inflows. 3 months after launch, 3MM customers had configured automatic distributions.
* Ran Stability for Money Management, conceiving of and delivering projects for robustness and engineering velocity. Helped reduce incident frequency and severity by 50% over 6 months.
* Member of the Technical Design Review working group. Defined acceptance criteria and served as reviewer for many projects across Cash.

### Founding Engineer, Tech Lead @ Welkin Health
Jan 2014 – Jan 2019
Joined Welkin’s founding team to launch its healthcare CRM, which ultimately served hundreds of thousands of patients across dozens of disease states.

* Developed Welkin’s initial systems, including the core web applications used by its first customers.
* Served as technical lead for multiple products, including Workshop (Welkin’s program development portal), apis, and integrations.
* Ran multi-team projects, including monolith decomposition, custom data definitions, and other greenfield CRM capabilities.
* Launched customers in a variety of domains, including mental health counseling, chronic pain management, and diabetes education.

### Software Engineer @ Notion
Jan 2014 – Jan 2014
Joined a team of five to refine core Notion systems ahead of the launch of 2.0.

### Platform Engineer @ Inkling
Jan 2011 – Jan 2013
Joined the team that launched Habitat, an application for developing interactive textbooks.

### Software Development Engineer @ Microsoft
Jan 2009 – Jan 2011
Joined the team that launched Amalga UIS, an application platform for hospitals.


## Education
### B.S.E. in Computer Science
Princeton University


## Contact & Social
- LinkedIn: https://linkedin.com/in/wschwa

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Source: https://flows.cv/williamschwarzenbach
JSON Resume: https://flows.cv/williamschwarzenbach/resume.json
Last updated: 2026-04-11