The Backend Engineering Show with Hussein Nasser

5 Backend Design Patterns for Managing Threads and Sockets

In this video I introduce 5 different design patterns for building backend applications. Each mode explains how a socket listener is established, a connections are established and how threads and connections are managed to read, write and process requests.

Page Tables

Page tables provide the mapping between virtual memory and physical memory for each process. This means it needs to be as efficient and as fast as possible. I explore the inner workings of page tables in this episode.0:00 Intro2:00 Virtual Memory ⁃ ⁃ 8:00 MMU10:00 Page Tables ⁃ ⁃ ⁃ ⁃ ⁃ ⁃ ⁃ 11:30 Single Table Byte Addressability   ⁃ ⁃ ⁃ ⁃ ⁃ ⁃ ⁃ ⁃ 16:00 Single Table Page addressability  ⁃ ⁃ ⁃ ⁃ ⁃ 19:00 Multi-level Paging (Radix tree) ⁃ ⁃ 31:00 Huge Tables ⁃ ⁃ 33:00 TLB ⁃ ⁃ Summary

CPU and Kernel Page Faults

Page faults occurs when the process tries to access a memory that isn’t backed by a physical page kernel raises a fault which loads a page. It happens on first access, stack expansion, COW, swap and much more. However it comes with a cost. In this episode of the backend engineering show I dissect the need and the cost page faults in the kernel. 0:00 Intro 4:00 Virtual memoryAbstraction of physical memoryMemory sharingAllow more processes to run , unused go to diskNuma, kernel can place memory near the cpu12:00 VMA areasText/code Data BSSHeapStack19:50 Kernel mode25:30 What is a Page fault?30:30 First access page fault33:00 Stack Expansion page fault34:30 CoW page fault38:00 Swap page fault39:39 File backed page fault40:29 Permission page fault 45:30 Summary

Amazon US-EAST-1 Outage in Details

On October 19 2025 AWS experienced an outage that lasted over a day, 10 days later we finally got the root cause analysis and we know exactly what caused the DNS to fail0:00 Summary 5:30 How did Dynamo lost its DNS?13:41 EC2 Errors 16:16 Network Load Balancer ErrorsRCA here https://aws.amazon.com/message/101925/

Graceful shutdown in HTTP

There are cases where the backend may need to close the connection to prevent unexpected situations, prevent bad actors or simply just free up resources. Closing a connection gracefully allows clients and backends to clean up and finish any pending requests. In this episode of the backend engineering show I discuss graceful connections in both HTTP/1.1 via the connection header and HTTP/2 via the GOAWAY frame. 0:00 Intro4:58 Why shutdown connection? 6:46 HTTP/1.1 Graceful shutdown12:26 Cost of HTTP/2 17:40 HTTP/2 GoAWAY frame23:40 SummaryLinkshttps://www.youtube.com/watch?v=fVKPrDrEwTI&t=1s https://chromium.googlesource.com/chromium/src/net/%2B/master/socket/client_socket_pool_manager.cc#76https://issues.chromium.org/issues/40555364https://issues.chromium.org/issues/40501721