Draft:Adrian Chadd

Early career and Internet Exchanges

Chadd's early career was rooted in the development of Australian internet infrastructure. He was a central figure in the operation of the **Western Australian Internet Exchange (WAIX)**, one of Australia's first major peering points. His work at WAIX involved managing the high-speed interconnects between regional ISPs and educational institutions, which informed his later work on scalable routing and caching.

He also spent significant time as a systems engineer at **AARNet** (Australia's Academic and Research Network). At AARNet, he focused on large-scale network performance and the deployment of transparent caching systems to manage the high cost of international bandwidth for Australian universities. These experiences at the exchange and backbone levels directly led to his long-term involvement with the Squid Web Cache project.^[2]

Wireless engineering and Atheros HAL

Chadd is a primary developer for the Atheros wireless driver stacks on both FreeBSD and Linux. While working at Qualcomm Atheros, he led the effort to modernize the Hardware Abstraction Layer (HAL) for 802.11n and 802.11ac chipsets. He was a vocal advocate for "de-blobbing" drivers, working to replace proprietary binary blobs with open-source C code.

His work on the **ath9k** (Linux) and **ath** (FreeBSD) drivers allowed for stable, high-speed wireless networking on non-Windows platforms. This effort was central to the Free Software Foundation (FSF) awarding its first-ever **"Respects Your Freedom" (RYF)** certification to a wireless-N adapter in 2013.^[3][4]

High-density content delivery at Netflix

Between 2013 and 2016, Chadd was a principal architect for the Netflix **Open Connect** project. Chadd’s engineering focus was on vertical scalability—getting more performance out of a single server to reduce power and rack space. He implemented **Receive Side Scaling (RSS)** and optimized the kernel's NUMA awareness, allowing FreeBSD to hit a benchmark of 100Gbps of encrypted TLS video traffic from a single socket.^[5][6]

Squid Web Cache development

For over 15 years, Chadd was a core maintainer of the **Squid Web Cache** project. He was responsible for the 2.7 stable branch, introducing a rewrite of the communications layer to use non-blocking I/O and significant optimizations to the COSS (Cyclic Object Storage System). These improvements allowed Squid to handle the rapid traffic growth seen by platforms like YouTube and Google Maps in the mid-2000s.^[2]

Community leadership

• FreeBSD Foundation: Chadd has been a recipient of multiple grants to modernize the 802.11 stack, including the 2023 project to support newer WiFi standards.^[7]
• The "Demon Bug" fix: In 2014, he patched a 30-year-old security flaw in the TCP stack that allowed for predictable sequence numbers, modernizing the kernel's random number generation.^[1]