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More from The Backend Engineering Show with Hussein Nasser All episodes →

1. 

   17 Oct 2025 · 26 min

   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 Intro 4:58 Why shutdown connection? 6:46 HTTP/1.1 Graceful shutdown 12:26 Cost of HTTP/2 17:40 HTTP/2 GoAWAY frame 23:40 Summary Links…

2. 

   3 Oct 2025 · 41 min

   Postgres 18 gets Async IO

   Postgres 18 has been released with many exciting features such as UUIDv7, Over explain module, composite index skip scans, and the most anticipated asynchronous IO with worker and io_uring mode which I uncover in this show. Hope you enjoy it 0:00 Intro 1:30 Synchronous vs Asynchronous calls 3:00 Synchronous IO 6:30 Asynchronous IO 10:00 Postgres 17 synchronous io 17:20 The challenge of Async IO in Postgres 18 20:00 io_method worker23:00 io_method io_uring 29:30 io_method sync 31:08 Async IO isn’t done! 3 1:30 Support for backend writers 32:36 Improve worker io_method 33:00 direct io support…

3. 

   13 Jun 2025 · 23 min

   Kernel level TLS

   Fundamentals of Operating Systems Course https://oscourse.winktls is brilliant.TLS encryption/decryption often happens in userland. While TCP lives in the kernel. With ktls, userland can hand the keys to the kernel and the kernel does crypto. When calling write, the kernel encrypts the packet and send it to the NIC.When calling read, the kernel decrypts the packet and handed it to the userspace. This mode still taxes the host’s CPU of course, so there is another mode where the kernel offloads the crypto to the NIC device! Host CPU becomes free. Incoming packets to the NIC are decrypted in…

4. 

   9 May 2025 · 10 min

   The beauty of the CPU

   If you are bored of contemporary topics of AI and need a breather, I invite you to join me to explore a mundane, fundamental and earthy topic. The CPU. A reading of my substack article https://hnasr.substack.com/p/the-beauty-of-the-cpu

5. 

   18 Apr 2025 · 28 min

   Sequential Scans in Postgres just got faster

   This new PostgreSQL 17 feature is game changer. They know can combine IOs when performing sequential scan. Grab my database course https://courses.husseinnasser.com

6. 

   4 Apr 2025 · 31 min

   Socket management and Kernel Data structures

   Fundamentals of Operating Systems Course This video is an overview of how the operating system kernel does socket management and the different data structures it utilizes to achieve that. timestamps 0:00 Intro 1:38 Socket vs Connections 7:50 SYN and Accept Queue 18:56 Socket Sharding 23:14 Receive and Send buffers 27:00 Summary

7. 

   6 Dec 2024 · 29 min

   The genius of long polling

   Polling is the ability to interrogate a backend to see if a piece of information is ready. It can introduce a chatty system and as a result long polling was born. In this video I explain the beauty of this design pattern and how we can push it to its limit. 0:00 Intro 0:45 Polling 2:30 Problem with Polling 3:50 Long Polling 8:18 Timeouts 10:00 Long Polling Benefits 12:00 Make requests into Long Polling 17:36 Request Resumption 21:40 Summary

8. 

   1 Nov 2024 · 39 min

   Six stages of a good software engineer

   You get better as a software engineer when you go through these stages. 0:00 Intro 1:15 Understand a technology 7:07 Articulate how it works 15:30 Understand its’ limitations 19:48 Try to build something better 27:45 Realize what you built also has limitations 32:48 Appreciate the original tech as is Understand a technology We use technologies all the time without knowing how it works. And it is ok not knowing how things work if interests isn’t there. But when there is interest to understand how something works, pursue it. It feels good when you understand how something works because you…

9. 

   25 Oct 2024 · 18 min

   This new Linux patch can speed up Reading Requests

   Fundamentals of Operating Systems Course https://oscourse.win Very clever! We often call read/rcv system call to read requests from a connection, this copies data from kernel receive buffer to user space which has a cost. This new patch changes this to allow zero copy with notification. “Reading' data out of a socket instead becomes a “notification” mechanism, where the kernel tells userspace where the data is.” This kernel patch enables zero copy from the receive queue. https://lore.kernel.org/io-uring/ZwW7_cRr_UpbEC-X@LQ3V64L9R2/T/ 0:00 Intro 1:30 patch summary 7:00 Normal Connection Read…

10. 

    18 Oct 2024 · 1 hr 2 min

    Cloudflare's 150ms global cache purge | Deep Dive

    Cloudflare built a global cache purge system that runs under 150 ms. This is how they did it. Using RockDB to maintain local CDN cache, and a peer-to-peer data center distributed system and clever engineering, they went from 1.5 second purge, down to 150 ms. However, this isn’t full picture, because that 150 ms is just actually the P50. In this video I explore Clouldflare CDN work, how the old core-based centralized quicksilver, lazy purge work compared to the new coreless, decentralized active purge. In it I explore the pros and cons of both systems and give you my thoughts of this system.…