Marc Brooker
marcbrooker.bsky.social
Marc Brooker
@marcbrooker.bsky.social
Serverless, databases, and serverless databases at AWS. Views my own.

Check out my blog: https://brooker.co.za/blog/
New short blog post, touching on how I'd redesign UUIDv7 to keep the database performance benefits while mitigating most of the downsides.

Short version: replace unix_ms with H(unix_ms, unix_ms >> 13 | salt).

Get yer extremely niche RFC commentary here: brooker.co.za/blog/2025/10...
Fixing UUIDv7 (for database use-cases) - Marc's Blog
brooker.co.za
October 22, 2025 at 11:21 PM
New blog post, reflecting on nearly seven years since the Firecracker launch, and how we're using Firecracker to power serverless databases (in Aurora DSQL) and infrastructure for AI agents (in Bedrock AgentCore).

Here's the post: brooker.co.za/blog/2025/09...
Seven Years of Firecracker - Marc's Blog
brooker.co.za
September 23, 2025 at 4:46 PM
Reposted by Marc Brooker
NULL BITMAP: Using Huffman Coding for Sampling Discrete Distributions: buttondown.com/jaffray/arch...
August 18, 2025 at 6:29 PM
Reposted by Marc Brooker
Seattle friends - in case you missed it: lu.ma/umtmqb38
The Seattle Systems group is hosting their very first meetup! @marcbrooker.bsky.social will be presenting Aurora DSQL.

Excited to see more systems groups popping up (thanks @eatonphil.bsky.social). My colleague @devhawk.net is co-organizing.
Transactions and Coordination in Aurora DSQL · Luma
Join us for a Seattle Systems talk that’s definitely worth your time as we welcome Marc Brooker, Distinguished Engineer at AWS, for a deep dive into the inner…
lu.ma
August 16, 2025 at 12:37 AM
People often ask me about the differences in architecture between Amazon Dynamo (the 2007 SOSP paper), DynamoDB (the AWS serverless NoSQL database), and Aurora DSQL (the AWS serverless SQL databases).

I memoized the response on my blog. brooker.co.za/blog/2025/08...
Dynamo, DynamoDB, and Aurora DSQL - Marc's Blog
brooker.co.za
August 16, 2025 at 1:42 AM
Reposted by Marc Brooker
If you're into databases and you're in Seattle, @marcbrooker.bsky.social is talking at Seattle Systems on Aug 21: lu.ma/umtmqb38
Transactions and Coordination in Aurora DSQL · Luma
Join us for a Seattle Systems talk that’s definitely worth your time as we welcome Marc Brooker, Distinguished Engineer at AWS, for a deep dive into the inner…
lu.ma
August 11, 2025 at 1:59 PM
LLMs are more powerful, more dependable, more efficient, and more flexible when deployed as a component of a carefully designed system.

New blog post: brooker.co.za/blog/2025/08...
August 12, 2025 at 4:06 PM
I had a great time talking to Ben and Will from Antithesis on the BugBash podcast about software testing and validation at AWS.

In this wide-ranging hour we talk deterministic simulation testing, fuzzing, formal methods, the history and future of testing, and much more.
August 6, 2025 at 5:27 PM
Reposted by Marc Brooker
Fun conversation with @jkxosound.com about where I think things are going in the AI agents space, Strands Agents, and rats 🐀
@clare.dev is one of the leaders making AI engineering simple and scalable at AWS. Had a great time chatting with her as we discussed Strands Agents and patterns like “Retrieval as a Tool”.
July 17, 2025 at 7:48 PM
Prototyping agents is easy, fast, and fun (especially if you use Strands). But how to you get them into production with all the scalability, security, and resilience you need?

We've been building Bedrock AgentCore to answer exactly that question. Check it out: aws.amazon.com/blogs/aws/in...
Introducing Amazon Bedrock AgentCore: Securely deploy and operate AI agents at any scale (preview) | Amazon Web Services
Amazon Bedrock AgentCore enables rapid deployment and scaling of AI agents with enterprise-grade security. It provides memory management, identity controls, and tool integration—streamlining developme...
aws.amazon.com
July 16, 2025 at 5:51 PM
I sat down with Darko Mesaros to talk about Kiro, specification-driven development, and putting AI-powered development in context of the history of computing.

Is an LLM a compiler? What is a spec? How are specs like SQL? Check it out: www.youtube.com/watch?v=OdD9...
✨ Beyond Prompts: The Future of AI-Assisted Development | Marc Brooker x Darko Mesaros 🧠
YouTube video by Kiro
www.youtube.com
July 14, 2025 at 11:17 PM
I've been using Kiro as my primary IDE for a couple months, and am super happy to see it launch.

Spec-driven development is super powerful. More reliable, more repeatable, and easier to control than prompt-based vibe coding.

Kiro's hooks are also pretty great. I use them to keep clippy happy :)
kiro.dev Kiro @kiro.dev · Jul 14
This is Kiro - the AI IDE that works on your messy, real-world projects. Other AI tools lose context when projects get complex. Kiro gives you spec-driven development that scales beyond prototypes.
Preview: kiro.dev/blog/introducing-kiro/?trk=6b579e54-2920-4e24-a25b-d3c887a6ffdf&sc_channel=sm

July 14, 2025 at 7:13 PM
Finally got to fixing the "related posts" feature in my blog. The Amazon Titan embedding model on Bedrock, plus cosine similarity, does a nice job:
July 12, 2025 at 12:55 AM
Reposted by Marc Brooker
🚀 New AWS Bites episode!

We tried Amazon #DSQL so you don’t have to (but you might want to) 👀

Luciano and Eoin put Aurora DSQL through its paces in #AWS Bites #Podcast Episode 145

🧵 Here’s what we found:
June 27, 2025 at 11:18 AM
New blog post, with some career advice: brooker.co.za/blog/2025/06...
Career advice, or something like it - Marc's Blog
brooker.co.za
June 20, 2025 at 6:14 PM
Here's the answer.

On the left, we see the great "exponential benefit at linear cost" impact of redundancy. But that quickly tapers off as the single point of failure dominates.

What can this teach us about building good HA architectures?
June 19, 2025 at 7:34 PM
Wrote a monte carlo simulator in Python. Took 300 seconds to run. Asked Q CLI to translate it to Rust, compile, and run. Took 48 seconds, including the translation, and gave exactly the same result.

Is Claude 4 the best Python compiler?
June 19, 2025 at 7:32 PM
Availability intuition quiz!

I have an architecture with N redundant components, each available 99% of time time, and one non-redundant component available 99.999% of the time.

Sketch, on the provided axes, the end-to-end availability curve versus N.
June 17, 2025 at 5:25 PM
New blog post, about some of my favorite papers from this year's HotOS program. Love Little's law? Hate fork? Think static analysis of shell programs sounds fun? Had enough of the f threshold model? Check it out for some papers to read: brooker.co.za/blog/2025/06...
Systems Fun at HotOS - Marc's Blog
brooker.co.za
June 2, 2025 at 4:42 PM
"You will never experience eventuality. Eventual consistency is an abstract concept, not a guarantee you can count on."
May 29, 2025 at 8:38 PM
Interested in how we test systems at Amazon?

In a new article in Communications of the ACM, Ankush and I write about the evolution of systems correctness and testing practices at AWS. We cover classic and formal approaches, and new ones like deterministic simulation.

cacm.acm.org/practice/sys...
Systems Correctness Practices at Amazon Web Services – Communications of the ACM
cacm.acm.org
May 29, 2025 at 3:38 PM
Aurora DSQL is now Generally Available! I couldn't be more proud of the team that brought DSQL to life, and excited about how our customers are going to build on it. 🧵
May 27, 2025 at 7:40 PM
Reposted by Marc Brooker
In a new guest post from #AWS Sr. Principal Engineers @nikomatsakis.com and Mark Bowes take us inside Aurora DSQL's development from scaling write operations without two-phase commit, to overcoming garbage collection hurdles, and embracing Rust. www.allthingsdistributed.com/2025/05/just...
Just make it scale: An Aurora DSQL story
AWS Senior Principal Engineers, Niko Matsakis and Marc Bowes, take us inside Aurora DSQL's development: scaling write operations without two-phase commit, overcoming garbage collection hurdles, and em...
www.allthingsdistributed.com
May 27, 2025 at 11:26 AM
Last week I had the privilege to give a keynote at the International Conference on Performance Evaluation (ICPE'25). It wasn't recorded, so I captured the key points as a blog post: brooker.co.za/blog/2025/05...
May 21, 2025 at 4:29 PM
Recently, one of our testing tools at AWS found an issue with transaction visibility in PostgreSQL, where the order that transactions become visible differs between the primary and replicas. Sergey Melnik dives deep on the AWS Database Blog: aws.amazon.com/blogs/databa...
Understanding transaction visibility in PostgreSQL clusters with read replicas | Amazon Web Services
On April 29, 2025, Jepsen published a report about transaction visibility behavior in Amazon RDS for PostgreSQL Multi-AZ clusters. We appreciate Jepsen’s thorough analysis and would like to provide ad...
aws.amazon.com
May 3, 2025 at 4:36 PM