Sijun Liu
Software Engineer at Google
Kirkland, Washington, United States
Summary
🤩
Rockstar🎓
Top SchoolSijun Liu is a software engineer with 12 years of experience building cloud identity, authentication, and deep learning infrastructure at Google, NVIDIA, Microsoft, and Oracle. He brings a strong theoretical background—a PhD in Mathematics from the University of Michigan—applied to practical systems like Azure authentication libraries, CUDA tooling, and Google Cloud services. His open-source contributions include bug fixes and protocol serializers for well-known Microsoft identity repos, demonstrating attention to interoperability and security edge cases in OIDC and WsFederation. Comfortable across C++, backend services, and identity metadata processing, he excels at turning complex cryptographic and protocol requirements into robust, test-covered implementations. Based in Kirkland, WA, he combines research rigor with product-focused engineering at scale. A less obvious strength is his knack for clarifying tricky callback and configuration semantics, improving long-term maintainability of authentication libraries.
12 years of coding experience
5 years of employment as a software developer
Doctor of Philosophy (PhD), Mathematics, Doctor of Philosophy (PhD), Mathematics at University of MichiganBachelor's degree, Mathematics, Bachelor's degree, Mathematics at Nankai University
English, Chinese
Stackoverflow
61reputation
1kreached
1answer
0questions
Github Skills (18)
javascript10
openid-connect10
net10
openidc10
oid10
authentication10
user-authentication10
dotnet10
security10
asp-net10
passportjs10
dotnet-core10
csharp10
testing9
xml8
Programming languages (7)
Github contributions (5)
AzureAD/passport-azure-ad
Jun 2016 - Mar 2018
The code for Passport Azure AD has been moved to the MSAL.js repo. Please open any issues or PRs at the link below.
Role in this project:
Backend Developer
Backend DeveloperContributions:15 releases, 215 commits, 213 PRs in 1 year 9 months
Contributions summary:Sijun contributed to bug fixes and clean-up tasks in the OIDC examples, focusing on client configuration files and the application logic (app.js). They added comments clarifying the acceptable formats for verify function callbacks and the role of parameters like `passReqToCallback`, `identityMetadata`, and `clientSecret`. The user also addressed path issues and updated README files, including instructions for setting up configuration files and running the application.
msal-jspassport-azure-ad
AzureAD/azure-activedirectory-identitymodel-extensions-for-dotnet
Mar 2017 - Jan 2018
IdentityModel extensions for .NET
Role in this project:Back-end Developer
Back-end DeveloperContributions:69 commits, 71 PRs, 236 pushes in 9 months
Contributions summary:Sijun contributed to the development of IdentityModel extensions for .NET. Their work included implementing a WsFed metadata serializer and associated test cases. The user also added a QueryHelper class and tests for WsFederationMessage tests. Further contributions involved converting KeyInfo to SecurityKey within the WsFederationMetadataSerializer and refactoring/changing structure of WsFederationRetrieverTest.
dotnetidentitymodel
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