John Velegrakis Email & Phone Number

Iráklion, Crete, Greece

Iráklion, Crete, Greece

Iráklion, Crete, Greece

In this role in Sunlight.io I was given the responsibility of designing and implementing the main data room of the company and also training the newly created ITOps department. Specific responsibilities that I was given: - Design/implement data center electricity topology with safety and fault tolerance - Design/implement of the whole data center networking infrastructure - Installation of hardware and cutting edge servers - Design/implement of Linux utility servers: routing, firewalling, security, load-balancing, DevOps services - Day-to-day operations after data center bring-up - Leading and training the new ItOps team that will manage the data center

Herakleion

I have the honor of leading a cross-domain, multi time zone team that brings the first cutting edge hardware accelerated NVMe-over-fabrics appliance from its inception, its design and development to the market as a complete product. Checkout Sunlight.io Photon at https://sunlight.io/products/photonIt is a challenge to lead team that includes a wide area of computer and engineering fields from - Hardware SoC design, - High-speed networking architecture,- hardware accelerated NVMe over network storage architeture, - Linux kernel development - User-space software engineering (back-end, APIs, etc). - End-to-end system validation & benchmarkingAlongside my management role my engineering tasks have included: - System design and architecture - FPGA System-on-Chip architecture and validation in Xilinx MPSoC FPGA chips - Low level 100GE Ethernet debugging and validation - Low level NVMe & PCIe debugging - arm64 Linux kernel driver development (network device drivers, and Xilinx FPGA management) - arm64 Linux kernel and runtime porting and tuning - Distributed applications development - User-space back-end management API - Electronics validation and chassis design & bring-up

Iráklion, Crete, Greece

I was leading a team of senior engineers - myself also engaged in Linux kernel driver development - that was designing and building a prototype from the idea to the Proof-of-Concept stage, as part of Onapp Emerging Technologies department.See Sunlight.io section for the continuation of the project.

I was leading a systems software team that had the responsibility of all software components that run on the new custom hardware (KMAX compute node) that contained Samsung Exynos CPUs and FPGA Zynq SoCs. In specific the team had the following tasks: - New PCB validation using custom software tests - Hardware prototype bring up - Boot loaders porting and modifications (U-Boot) - Linux kernel porting and modifications - New Linux kernel driver development (10G network, 1G network, UFS, SM bus, UART, voltage/frequency scaling, Adaptive Supply Voltage support, etc) - Control/management user space services - KMAX compute node API

Iráklion, Crete, Greece

My responsibility in this position involved the following tasks: - Design the portion of the KMAX compute node PCB that contained the two FPGA chips and their connection to DDR memory, SM bus and 1G Ethernet. (Cadence Allegro) - Design the PCB of a mini-feeder board that routed all the external connections of the KMAX compute node (Power, 10G Ethernet links, 1GE Ethernet links, UARTs, SM buses and control signals) (Altium). - Design the new version of the main voltage regulation circuit and control logic for the Exynos CPU of the KMAX compute node.

In this role I was responsible for software integration to the new prototype of the company, the KMAX compute node. Some of the major tasks involved:On the Xilinx Zynq FPGA: - Software stack porting: FSBL, U-Boot, Linux, RootFS, etc - Linux kernel network driver for the Xilinx Zynq ARM A9 CPU - Linux drivers for the Xilinx Zynq ARM A9 CPU that controlled FPGA logic using the AXI bus.On the Samsung Exynos CPU: - Software stack porting: U-boot, Linux, RootFS - Linux kernel 10G Ethernet network driver - Custom drivers for direct communication with the Xilinx Zynq FPGA using custom interconnects. - Linux PCIe core drivers modifications.

Greece

Iraklion

Irakleion

Master Of Science (Msc), Distributed And Parallel Systems

Bachelor'S Degree, Computer Science, 7.3