1. DAVID SACERDOTE das33@cornell.edu | (781)856-5640
www.linkedin.com/in/DavidSacerdote
SUMMARY Software engineer energized and captivated by large-scale problems impacting complex
systems, including distributed databases, huge transaction volumes and structuring of large
amounts of scattered information into useful data.
 Team experience in Agile and Waterfall.
 C, C++, Python, and Java, among other languages.
PROFESSIONAL
HISTORY
Facebook, Content Delivery Network (CDN) team
Software Engineer
 Improved overall speed-to-deliver content, resulting in a 5% increase in the fraction of
photos rendered successfully in Asia.
○ Analyzed packet captures to understand real-world performance of mobile devices in
emerging markets to explain high time-to-display for images as well as a lower
success rate for image rendering than in the US.
○ Identified upload bandwidth limitations on 2g cell networks as a key cause of
retransmitted HTTP requests, causing multi-second delays in content loading.
○ Identified client-side cache issues which caused clients to make unnecessary
requests for content.
○ Modeled the performance of HTTP push in advance of committing multiple engineers
across different teams to work, providing accurate performance estimates before start
of work.
○ Implemented datacenter-to-edge push, including a tracking system to prevent pushing
content already in the CDN edge cache, eliminating a round trip between the edge and
datacenter. In Asia, this cut the delay associated with a CDN cache miss by 180+
milliseconds.
 Designed and implemented a system allowing Facebook to take advantage of the
progressive jpeg format to allow the delivery to eliminate the need to increase the CDN
cache working set size for Instagram when moving from 640 pixel images to 1080 pixel
images and delivering different-sized images to devices with different sizes of display.
○ Patent pending.
 Developed a system for measuring relative performance of a mix of memory-constrained
and CPU-constrained equipment so that we could automatically load-balance in clusters
with heterogeneous hardware.
Cisco Systems, Border Gateway Protocol (BGP) Team
Software Engineer
Added features and maintained Cisco’s implementation of the Border Gateway Protocol.
 Implemented router side of the router-RPKI (Resource Public Key Infrastructure) protocol
(RFC 6810) during the drafting of the RFC. This was the first implementation released,
completed as the draft was undergoing revision.
o Provided optional cryptographic authentication of the originator of a route,
preventing organizations from mistakenly advertising a route to address space
belonging to somebody else.
o Implemented a mock server to conduct integration testing prior to the availability of
third party servers.
o Collaborated with Cisco’s IETF representative to improve draft protocol prior to
standardization.
o Awarded US patent 8640236 based on the project’s innovations.
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2014-2016
2008-2014

2. DAVID SACERDOTE das33@cornell.edu | (781)856-5640
www.linkedin.com/in/DavidSacerdote
 Worked with customer support to proactively address customer issues at the engineering
level, resulting in substantial increase in customer satisfaction as measured by a marked
decrease in escalation rates to upper management.
 Upon joining the team, refactored code and fixed a large backlog of known unaddressed
bugs for increased reliability. Delivered such a high level of reliability post-refactor that
customers began using product in applications in which human life was at risk, including
back-end transport for 911 systems.
 Took over development Per-CE Label Mode Allocation Project, allowing the allocation of
Multi-Protocol Label Switching (MPLS) labels on a per-endpoint basis, supplementing the
existing per-net and per-VRF allocation mechanisms, providing feature parity with a
competitor’s product.
Cisco Systems, DHCP/DNS team
Software Engineer
Responsible for maintaining and extending the DHCP relay and server inside Cisco IOS as well
as the limited DNS support inside IOS.
Cisco Systems, Authentication, Authorization, and Accounting
Software Engineer
Identified key bottlenecks that limited simultaneous users on a device, and then completely
rewrote the software to allow for multiple orders-of-magnitude scaling improvements.
Sun Microsystems
Summer Intern
Wrote software to integrate smart card use with existing authentication mechanisms.
Secure Networks, Inc.
Software Engineer
Co-founder of a start-up which produced an auditing tool that enabled enterprises to audit their
network for known security problems. Company subsequently purchased by Symantec.
EDUCATION &
AWARDS
Cornell University
Bachelor of Arts in Computer Science. Minor in Philosophy.
US Patent #8640236, Performing a Defensive Procedure in Response to Certain Path
Advertisements.
Patent Pending, Systems and methods for providing progressive images based on data range
requests.
INTERESTS Avid outdoor enthusiast and nature photographer. Regular back-packing and cycling
expeditions into open space preserves. Longer trips have ranged from cycling a loop around
the northern half of California, to backpacking trips in the coast range and Sierras. My
photography has been published in textbooks and academic papers.
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2006-2008
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1999
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