Extensive experience of build out very large scale infrastructure with both bare metal and cloud with strong technical background from over 17 year industry experiences as OS / kernel / system engineer specialized in LINUX / MAC OSX /Virtualization Kernel such as ESX and XenServer / embedded RTOS kernel developments. Specialties: LINUX / MAC OSX / Virtualization kernel development, multi-threaded programming, SCSI/SAS/SATA/FC/iSCSI, PCI/PCI-X/PCIe (MSI/MSI-X), RAID device driver development for data network storages (NAS/SAN). Managing and supporting Engineering team to build very large scale infrastructure @Twitter!

Staff System Engineer @ Hands-on Engineering Manager -- lead and manage the Hardware & System Reliability team; a group of talented engineers who are responsible for all production reliability aspects of hardware, BIOS, firmware, and OS to a very large number of Twitter’s servers: ● Supporting SRE (Site Reliability Engineer) team to handle all system related issues that impacted Twitter infrastructure and applications. ● Managing end-to-end system Bios and firmwares updates to large number of servers: build the hardware quality & sustaining processes, coaching, communicating, deciding, and directing the hardware quality team. and implemented the better quality control and incident avoidance. ● Built automation frameworks to monitor, and data mining server health and quality data throughout the fleets. Our team provides quality data such as HW Annual Failure Rate (AFR), hardware component (SSD, hard disks, memory, etc) issues and the failure statistics per each hardware platform / vendor / etc. From September 2014 to Present (1 year 4 months) San Francisco Bay AreaSenior System Engineer @ Hosting everyone to tweet! Follow me on twitter @diepvule From September 2012 to September 2014 (2 years 1 month) San Francisco Bay AreaSystem Engineering manager @ Managing and supporting system engineer team (including across geography members) to build tools and support the high availability & serviceability of Zclound (Zynga private cloud) Architected and led a small system engineer team to build Zynga bare-metal and virtualized server farms – successfully build two new Zynga’s datacenter in California with about 30,000 servers online and in service for Zynga’s games. Bellow are couple highlights: • System performances, power-consumption benchmarks, and capacity planning to build our new Zynga gaming infrastructures - Zcloud (both XenServer and bare metal provisioning), replacement of Amazon’s EC2, S3. • Worked with OEMs, and ODMs on new system architecture such as new intel CPU architectures (SandyBridge at the time) to build Zynga white box servers. SeaMicro was also one of the considered architecture. • Build tools to automatic provision, maintain, and support the high availability of Zynga’s infrastructures and services. Successfully provisioning and supporting more than 40,000 production servers in all datacenter locations with different hardware from multiple vendors. • Build a system burn_in framework to automate component performance qualification, and insure systems with high quality before they entering their provision life-cycle and hand-off to service owners. • Build out-of-band with IPMI commands working with Ganglia, and Nagios to monitoring and support system administrator operational. Standardized what I called MORE (‘Minimum Operational Requirements or Equivalents’) for BMC/IPMI from all vendors. • Debugged, analyzed and root-caused Linux kernel crashes, and patched in kernel / driver bug fixes. Successfully handle and gave long term solution to top CentOS kernel issues, such as the well known "200 days or so crashes" of CentOS 5.4, 5.5. • Created "Splunk" dashboards to monitoring system / kernel issues, and proactively plan out solutions to such distributive known kernel issues. From May 2011 to September 2012 (1 year 5 months) San Francisco Bay AreaSenior Software Engineer @ Developed new features requests, handled customer-escalations (active member of tiger team) for storage and network related issues in ESX server products (2.5.x, to 5.0.x) from a large customer / partner base, included IBM, HP, Fujitsu, and DELL. Specialized in iSCSI, NFS, SAS, SATA, tape, USB, and multi-path storage drivers in ESX kernel virtualization environment. A few high-lines are listed below: • Designed and enhanced the SCSI multi-path I/O modules (internal named PSA -- Plug-in Storage Architecture) of the virtual machine kernel (vmkernel) to protect against path failures. Major performance improved ESX boot time by introduced a target/LUN parallel discovery mechanism. This has successfully resolved a lot of major customer issues on older produces. • Implemented SCSI LUN reset feature in software initiator iSCSI driver for vmkernel multi-path codes to cleanly doing path-failover without corrupting concurrently IO on other iSCSI LUNs behind the same SCSI-target. This feature was successfully resolved a lot of customer’s path- failover issues on software initiator iSCSI storage. • Designed and implemented storage device/patch claiming rules to enhance the flexibility for ESX server to manage its devices/patches. Successfully handling dynamically the conflicting requirement from EMC and Dell-Equallogic for their management LUNs just by a configuration option change for their devices/patches in ESX server. Device/patch claiming rule mechanism has become a major feature in ESX4.0.x to enable major vendors’ storage plug-in modules in ESX environment – EMC’s storage multipath module (EMC’s Powerpath) is loading at the same time with VMWare in-house storage multipath module; device/path claim rules to determine which storage module to claim the paths to a particular storage LUN. From February 2007 to May 2011 (4 years 4 months) Senior Software Engineer @ LINUX OS / MAC OS X kernel development, multi-threaded programming, SCSI/SATA, PCI/PCI-X/PCI-EXP, RAID (0,1,10,5, N-Way Mirror) device driver development for SATA storage products including SteelVine product line. · Architected and deployed a monotonic code-base (SCSI) driver architecture, a single driver source tree, to control all Silicon-Image’s PCI, PCI-X, PCI-Express to S-ATA Host Bus Adapters (HBA), supporting multiple Operating Systems (WINDOWS, LINUX, Netware, MAC OS X), on multiple platforms (32-64 bit architectures of Intel, AMD, and Power PC). This resulted in great cost reduction of software developing, testing; alleviated product releases managing. This architecture helped to re-use driver codes and software components for different platforms and OS, shorten software developing cycles. Products: Sil3112, Sil3114, Sil3124, Sil3131, Sil3132. · More ... Original FW developer of the SATA port-multiplier named SiliconImage-SteelVine. From May 2004 to February 2007 (2 years 10 months) Senior Software Developer @ • Software architecture/leader of PDC’s Parallel ATA/Serial ATA RAID (0, 1, 10) storage controller products. Managed daily activities and leaded a group of four software engineers to sucessfully delivered the beta shipment on tight schedule. • LINUX/FreeBSD Device Driver Developer for PDC’s “Universal Host Bus Adapter” (UHBA) to control Parallel ATA/Serial ATA drives. Successfully delivered high performance, high reliability RAID SCSI subsystem device drivers. • Improvised software solutions/workarounds to hardware problems. With strong understanding of hardware and integration issues, I have been contributing a number of algorithms and methods to both hardware and software to roll out a high performance, high level of flexibility SATA RAID storage controller products. • Technical lead of PDC’s software group and offshore-software-group (SPSoft Inc. in India) From January 2003 to May 2004 (1 year 5 months) Senior Software Developer @ Kernel/System Manager/FiberChannel Device Drivers developer for 3PARdata network storage system. I was employee 34th. • Created detailed algorithm to eliminate data inconsistencies, prevent data loss, and perform data recovery under uncontrolled shutdowns, along with data storage managment features. This resulted in successful customer critical quality tests for Beta and General Availability shipments. • Established and deployed infrastructure for communication interface protocols, such as between BIOS and 3PAR controller node kernel software using SMI, and I2C protocols; between User and Kernel of LINUX OS using IOCTL; between clients and the 3PAR storage box using TCP/IP with buffer size change on demand; between the JBOD chassis and the System Manager software. • Designed and rolled out new LINUX kernel services contain monitoring and reporting the system‘s environment, logging and enabling proactive and predictive customer support actions; From February 2000 to December 2002 (2 years 11 months) Software Developer @ Server developer for “Accrue Insight“ product: • Developed and implemented DAS (Database Access Servlet) for “Accrue Insight“ product. Successfully provided a set of Application Protocol Interface (API) that allowed UI layer to connect to Accrue Warehouse. • Restructured Accrue's data Analyzer component, a core of “Accrue Insight“ product that parsed and transformed web data to database schema-formats automatically. • Improved loading data rate into Accrue Warehouse (ORACLE / REDBRICK Databases) by 20% by optimizing the loader component. • Established a security protocol using MD5 and RC4 algorithms to safely transfer data from Collectors (remote web data collectors) to Accrue Warehouse. Setup entire environment to facilitate “Accrue Insight“ product release. Determined product-build cycles. From May 1997 to January 2000 (2 years 9 months)

B.S., College of Engineering (EECS) @ University of California, Berkeley From 1995 to 1997 Diepvu Le is skilled in: Virtualization, Kernel, Linux, Storage Area Networks, Mac OS X, VMware, Storage, iSCSI, Clustering, Device Drivers, SCSI, VMware ESX, RAID, SATA, Perl