Dimitar Hristov

⧫ Managed the bring-up and operations for HGX H100/200, GB200 and GB300 clusters with 550k GPU capacity. ⧫ Started to prepare new Vera Rubin clusters. ⧫ Oversaw bring-up and operations for the entire clusters. ⧫ Led deployments for DGX SuperPODs and provided customer training on RDMA and GB architecture. ⧫ Troubleshoot complex latency and performance issues, resulting in approximately 20% optimizations for customer workloads. ⧫ Defined telemetry structure and developed ZTP scripts for provisioning and configuring GB and Hopper clusters. ⧫ Contributed the network design and PoC for interbuilding connection ⧫ NCCL performance troubleshooting ⧫ Team onboarding

⧫ Managed capacity increase for 9 regions on the datacenter circuits to the backbone ⧫ Developed new automation workflows for backbone link capacity increase ⧫ Reduced the overall runtime of all workflows by 30% ⧫ Designed expansion for workflow for provisioning BGP policy for greenfield regions which cut delivery time by 70% ⧫ Resolved race condition conflicts between parallel workflow execution and eliminated the need to manual recover corrupted data by 50% ⧫ Coached new team members and did more than many code reviews ⧫ Expanded internal tools to support new BGP policy design which shorten the update time by 30% ⧫ Synchronized activities between 4 different teams to standardize processes and increase efficiency by 30%

⧫ Participated into the launch of Catalyst 9000 series of switches ⧫ Wrote two white papers QoS and Queuing and SISF used for customer deployments ⧫ Consulted and discussed multiple end to end network design questions for customers ⧫ Presented at CiscoLive Catalyst 9400, 3850 Architectures (distinguished speaker) ⧫ Delivered multiple presentations of Security features for Catalyst switches based on UDAP ASIC, IBNS 2.0 + ISE, MACsec, IPsec, Stackwise Virtual ⧫ Trained many interns, supported them during their onboarding ⧫ Prepared training materials on latest Catalyst 9000 Innovations over 5 years of development

⧫ Participated in development of Nexus 7000/7700 data center switches ⧫ Validated and improved QoS and Queuing, ASIC Forwarding implementation on Linecards M3,M2/F3/F2 by 95% ⧫ Resolved more than 1000 customer issues when they integrated Nexus 7K products ⧫ Developed automated regression tests via PyATS, resulting in 80% reduction in regression tests time. Using Agile with Scrum, resulted in improved planning, ownership and reduced development time by 50%

⧫ Resolve complicated switching problems for Catalyst and Nexus Series of switches in short and limited time during service down situations. ⧫ Diagnosed and root caused the problems, then dug down into the programming of the switches to apply workaround or resolve the problems. ⧫ The impact of my work was to stabilize and return the network into normal operational state for less/minimum time. Enabled teammates to be fast and efficient with their work and troubleshooting approach

⧫ Device Testing for Catalyst 6500 – Feature Manager – execution of manual testing for latest Catalyst 6500 IOS/ION software. Working experience on NAT, PBR with other options, Reflexive ACL, standard/extended ACLs, MACPBF, Lawful Intercept, PACL, VACL, RACL, DAI, DHCP Snooping, IOS SLB, RPF with ACL, WCCP, SSH, Auth Proxy, WebAuth, OAL, IP DSCP sequential, DHCPv6 PD, DHCPv6 Relay, ⧫ Testplan development for Whitney 2 and Half Dome CEV. Familiar with all problems when uploading document in TIMS ⧫ Wrote Automated TCL scripts for testing MACPBF, guided other engineer how to develop TCL with latest IxNetwork API ⧫ Integration between TestSmart and ATS.

⧫ Designed and implemented network infrastructure solutions for our corporate clients: o Daimler Chrysler Bulgaria, BalcanStar –The Project is based on Cisco AVVID and converge Data and Voice between 8 countries. DMVPN with appropriate QoS solution was used to provide secure inter site connections. In one of the Site (Reutlingen, Germany) was installed Call Manager 4.2 with Cisco Unity 4.0. Into the rest 7 sites were deployed SRST routers with appropriate interfaces to PSTN. The project will be extended to 33 countries in EU. o DSK Bank, EURO Bank, Union Bank, InverstBank, bTV, gTV, Automotor Corp and Nova TV – As a team leader, I managed the integration of VoIP and LAN infrastructures into their new headquarter offices. ⧫ Generated profit and loss, and return of investment reports for individual clients, and recommended either their continued existence or closure based on their findings.

⧫ Assumed Leadership in migration from MS Exchange 5.5 to MS Exchange 2003, Mail Boxes Migration.⧫ ⧫ Installation & Administration of Windows NT 4 / 2000 / 2003 server implementing POP3, IMAP4, SMTP and HTTP (OWA), performing offline de-fragmentation on a regular basis, Apache 2.0.40, IIS 6. ⧫ Implemented Distributed File System on replication servers for 99.99% uptime. ⧫ Configuration of remote control/management applications - Terminal Services, Configuration of Windows 2000 / 2003 Active Directory services, implementing Group Policy Management using Function-based Organizational Units as well as logon and logoff KIX scripts, ⧫ Tested a plethora of applications using VM Ware running multiple Operating Systems simultaneously. ⧫ Deployed the application in staging, in production, following change management practices and 24/7 support, worked in shifts. Demonstrated a high level of commitment to company’s success by constantly reducing downtime, upgrading company machines, troubleshooting peripherals, installing client and company's proprietary software and patches as and when necessary. ⧫ Built and maintain Visio documentation for current enterprise topology ⧫ 24/7 support, worked in shifts. Demonstrated a high level of commitment to company’s success by constantly educing downtime, upgrading company machines, troubleshooting peripherals, installing client and company's proprietary software and patches as and when necessary.