Alex Xu

• Advanced Object Oriented Programming (A+)
• Design and Analysis of Algorithms (A+)
• Fundamentals of Data Structures (A+)
• Computer Architecture (A)
• Database Management Systems (A+)
• Applied Cryptography (A+)
• Mathematics of Cryptography (A)
• Network Security (A+)

• Advanced Object Oriented Programming (A+)
• Design and Analysis of Algorithms (A+)
• Fundamentals of Data Structures (A+)
• Computer Architecture (A)

• Database Management Systems (A+)
• Applied Cryptography (A+)
• Mathematics of Cryptography (A)
• Network Security (A+)

Developed several core projects and provided extensive consulting on C, Linux, git, and networking.

• built a Buildroot-based minimal Linux infrastructure for the launch of a multi-link VPN product
• created a fully automated high-speed operating system installer for x86 systems using BusyBox sh
• created a tool for remote Linux in-place replacement using POSIX sh and BusyBox
• developed a GitLab CI process for generating the deployable image

Co-developed a Django web platform for worldwide crowdsourced hydrographic data collaboration.

Taught lab sessions for 48-student Android/web development course.

Reported, documented, and contributed fixes for issues including Operation not permitted in Docker, sh: write error: Invalid argument, and Raspberry Pi doesn't boot, 7 blinks. Proposed changes including -fno-plt for x86 and x86_64, compressing debuginfo, and reconsidering -Os.

Implemented correct global-dynamic TLS support, fixing musl compatibility.

Implemented copy_file_range support, shrinking Wine prefixes from 200 MB to less than 1 MB.

Reported issues and submitted fixes: lkml, linuxlists. Diagnosed Cargo issue 9739 to a long-standing kernel bug, and fixed the underlying issue, resolving a deadlock in GNU Make and similar jobservers.

Discovered and reported an issue allowing full host device access from guests with virtiofsd enabled.

Built a concurrent Python web font subsetter with automatic pixel-perfect verification.

Built a concurrent Python pygments microservice, reducing TTFB from 1.1s to 0.15s on cgit.alxu.ca. Improved portability and security and reduced LOC by 66% by switching from http.server to aiohttp.

Built a C tunnel to simulate datagrams using TCP packets, fixing TCP-over-TCP overhead.

Implemented cross-bit ptrace, migrated from qmake to CMake, and refactored code.

Built a minimal .NET registry editor.