Charles Ferguson
Senior Full Stack Engineer at Calendly
Sharpsburg, Georgia, United States
Summary
👤
Senior🎓
Top SchoolCharles Ferguson is a Senior Full Stack Engineer with 16 years of experience building scalable web and AI-driven products, currently shaping integrations and features at Calendly. He combines hands-on implementation—from CPU emulator internals and DevOps test harnesses to frontend SPAs—with strategic product leadership that shifted Springbot from sales-led to product-led growth. His work spans backend resilience (contributions to the Unicorn CPU emulator), robust automation and documentation (Ansible), and CLI/test infrastructure for fish-shell, reflecting a comfort with low-level systems and high-level UX alike. He has a track record of reducing operational costs through architecture simplification and CDN/Big Data optimizations while shipping Generative AI and fraud-detection tooling. Known for leading teams without losing coding velocity, he bridges product strategy and execution to improve user outcomes and developer efficiency. Based in Sharpsburg, GA, he brings a pragmatic blend of curiosity and systems-level insight to complex engineering challenges.
16 years of coding experience
12 years of employment as a software developer
Bachelors Computer Science, Bachelors Computer Science at University of West Georgia
Stackoverflow
677reputation
106kreached
2answers
22questions
Github Skills (29)
test-automation10
python10
cpu10
command-line-interface10
bash10
c1110
x8610
c1710
x86-6410
command-line10
ansible10
arm10
ansible-galaxy10
shell10
emulation10
Programming languages (14)
Github contributions (5)
unicorn-engine/unicorn
Jan 2020 - Jan 2022
Unicorn CPU emulator framework (ARM, AArch64, M68K, Mips, Sparc, PowerPC, RiscV, S390x, TriCore, X86)
Role in this project:
Back-end Developer
Back-end DeveloperContributions:2 reviews, 5 commits, 5 PRs in 2 years
Contributions summary:Charles's contributions primarily focused on improving the functionality and stability of the Unicorn CPU emulator. They fixed bugs related to code tracing, early exits from emulation, and hook behavior. Additionally, the user implemented access to the ARM SPSR register, expanding the emulator's ability to handle specific ARM architecture features. The changes included modifications to core CPU execution and hook handling, demonstrating in-depth knowledge of the emulator's internal workings.
emulatorglibcarm64cpus390x
fish-shell/fish-shell
Jun 2017 - Jun 2017
The user-friendly command line shell.
Role in this project:DevOps Engineer & Test Automation Engineer
DevOps Engineer & Test Automation EngineerContributions:7 commits, 1 PR, 10 comments in 1 day
Contributions summary:Charles focused on enhancing the testing infrastructure and command-line interface of the fish shell. Their work includes adding a test harness to validate the shell's command invocation, specifically testing the new `--init-command` feature. They also added tests for other command line options and fixed issues related to system-specific output, contributing significantly to the robustness and reliability of the fish shell project's testing framework. These changes demonstrate a focus on automation and ensuring the correct behavior of the shell's command-line interface.
bashterminalfishcommand-lineshell
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