Systems engineer who lives below the abstraction layer. Networking, kernel internals, performance engineering — I write about the things most people hand-wave past.https://harshith.in/en-usSun, 19 Apr 2026 05:07:56 GMTharshithsunku@gmail.com (Harshith Sunku)harshithsunku@gmail.com (Harshith Sunku)https://harshith.in/blog/ebpf-production-debugging/https://harshith.in/blog/ebpf-production-debugging/How eBPF changed production debugging — attaching probes to kernel functions, tracing syscalls, measuring latency histograms, and XDP packet processing, all without touching application code or rebooting.Sat, 21 Mar 2026 07:53:59 GMTebpfkernelperformancedebugginglinuxhttps://harshith.in/blog/esp32-mqtt-wake-on-lan/https://harshith.in/blog/esp32-mqtt-wake-on-lan/Using an ESP32 and ESP-IDF to build a network-aware Wake-on-LAN trigger — power on machines remotely over MQTT without an always-on server in between.Sat, 21 Mar 2026 07:53:59 GMTembeddednetworkingsystemschttps://harshith.in/blog/real-mode-bootloader-assembly/https://harshith.in/blog/real-mode-bootloader-assembly/The first 512 bytes that run when your machine powers on. A walkthrough of x86 real mode, the BIOS interrupt interface, segment:offset addressing, and what it takes to load a second stage.Sat, 21 Mar 2026 07:53:59 GMTassemblysystemskernellinuxhttps://harshith.in/blog/thread-safe-logging-c-lock-free/https://harshith.in/blog/thread-safe-logging-c-lock-free/Inside ThreadSafeCLogger: how to build a high-performance logging library that doesn't serialize your threads, using per-thread SPSC ring buffers and careful memory ordering.Sat, 21 Mar 2026 07:53:59 GMTcthreadingperformancesystemshttps://harshith.in/blog/software-tcp-ip-stack-c/https://harshith.in/blog/software-tcp-ip-stack-c/A deep dive into implementing a functional TCP/IP stack entirely in software — covering Ethernet framing, ARP, IP routing, TCP state machines, and the painful lessons learned along the way.Sat, 21 Mar 2026 07:53:59 GMTnetworkingctcp-ipsystems