Walmart | Staff Engineer 2 | July | Awaited

eBPF XDP Engineer Staff Engineer (golang)

Round1

• GUE Tunnel, Skewing
• Sort array using 1 stack only and 1 variable.

Round2

• TCP characteristics
• How can connection be closed except FIN? RST
• TCP States (TIME_WAIT)
• When packet is received by kernel (on NIC), what all happens till it reaches application.
• How packet reaches server when we type google.com in browser
• valgrind
• gdb multithreaded
• SDN Design

Round3 (Manager)

• Explained about Role
• Asked about project
• Am I willing to take challenge

Round4 (Design)

• Janiper, AMD, Red Hat Projects.
• Difference between DPDK & eBPF xdp on (CPU Utilization, Interrupts etc)
• Design a Rate Limiter, which sits in front of 4 proxies. It should limit the traffic and should be available
  • Using Sliding window
  • Proxy will inform Rate limiter squeezing the window size using Flag as in SYN packet when it cannot process more packets.