Yan Cui

TIL web neural network API, an emerging web standard for building in-browser AI apps that lets you use those new NPUs in phones and laptops.

w3.org/TR/webnn

I have not paid a ton of attention to the uproar over RTO policies, bc we are all in on distributed teams and not going back.

My impression (via social media) has been that these were shadow layoffs.

Last month I asked an investor why they are doing RTO. He said: "Retention, mostly. And morale."

Dude, this is amazing and thank you so much for your support over the last 12 months!

How to use Neon and ephemeral environments to simplify serverless development Understand the value of ephemeral environments, and how you can use Neon and ephemeral environments to simplify serverless development

I've been diving into Neon and I like what I see!

Here's how you can use Neon with ephemeral environments to simplify serverless development.

theburningmonk.com/2025/04/how-...

Saying "coding is dead" is missing the point. Coding isn’t just about producing code, it’s also a way of thinking.

It teaches us structure, systems thinking, abstractions and problem decomposition.

If you don’t learn those skills, AI won’t make you productive, it’ll make you dependent.

I finally binged The Orville, it was time well spent, especially seasons 2 and 3!

So high on Star Trek nostalgia right now 😅

YouTube video by Master AWS with Yan Introducing LocalStack v4

I recently spoke with Waldemar Hummer to find out what's new in LocalStack v4 - e.g. visualize and trace event-driven arch end-to-end, or create snapshots of your system.

It's crazy how fast they are innovating!

youtu.be/vVUBnXD6eto

:-P

Through chaos experiments, the Lambda team reduced response time to an AZ outage by 90%! 🤯

The pros and cons of Lambdalith Learn about lambdalith and how it helps you build serverless APIs with AWS Lambda, as well as its pros and cons.

"Lambdaliths have slower cold starts"
"Lambdaliths have fewer cold starts"

Both can be true, but neither is entirely correct. It depends on several factors.

In my new post, I explain these nuances so you can make a better choice.

theburningmonk.com/2025/03/the-...

YouTube video by Master AWS with Yan How to Build a Multi-Tenant System (Best Practices)

I spoke with Khawajas Shams about building large-scale (think millions of TPS) multi-tenant systems.

We talked about pros & cons of cell-based architectures, how it reduces the blast radius, and techniques for building high-throughput systems e.g. core pinning

www.youtube.com/watch?v=8jte...

Nice to see a full house at the serverless days Manchester 💪

How we built an AI code reviewer with serverless and Bedrock Slides for my talk at the Serverless London meetup on 12-Feb-2025

Thank you to everyone who attended my talk at the Serverless London meetup last night 🙏

Here are my slides for those who couldn't make it.

You can try Evolua for free at evolua.io. We'd appreciate your feedback!

speakerdeck.com/theburningmo...

How we built an AI code reviewer with serverless and Bedrock Explore the high-level architecture of Evolua, an AI code reviewer built with Bedrock and serverless technologies, and what we learnt

New post: How we built an AI code reviewer with serverless and Bedrock

My biggest lesson learnt is that, at least for our use case, LLM is the easy part and there's still a lot of "app" in an "AI-powered app"!

Wiz Research Uncovers Exposed DeepSeek Database Leaking Sensitive Information, Including Chat History | Wiz Blog A publicly accessible database belonging to DeepSeek allowed full control over database operations, including the ability to access internal data. The exposure includes over a million lines of log str...

Wiz found a publicly accessible ClickHouse database linked to DeepSeek, completely open and unauthenticated, exposing sensitive data like chat history 🤦‍♂️

www.wiz.io/blog/wiz-res...

YouTube video by Yan Cui Hookdeck has built a better Developer Experience than EventBridge

I spoke with the co-founder of @hookdeck.com to find out what it can do, and it's impressive!

There is a lot of focus on DX for building Event-Driven Architecture, and EventBridge can learn a lot from them.

Have a look for yourself.

www.youtube.com/watch?v=-jmM...

Yan Cui | AWS Serverless Hero Connect with Yan Cui, experienced engineer, AWS user since 2009, and frequent author of serverless-focused topics.

AWS Hero status renewed for another two years 😇

aws.amazon.com/developer/co...

This is AWESOME!!

EventBridge now delivers events to cross-account targets directly without having to send them to the default bus in the target account first.

More details here:
aws.amazon.com/about-aws/wh...

Here's a mindmap of everything we'll cover in my 4-week boot camp starting on Monday.

Are we missing anything that one should know for running serverless workloads in production?

Detailed curriculum here: productionreadyserverless.com#curriculum

YouTube video by Yan Cui EventCatalog REVOLUTIONIZES Governance in Event-Driven Architectures | ft. David Boyne

We're back with a new episode of real-world serverless.

I spoke with @boyney123.bsky.social about the hard parts of building event-driven architectures and how EventCatalog can help with event documentation, discovery, versioning, visualization and testing.

www.youtube.com/watch?v=ZVl7...

did he say what caused the spike?

Thank you 🙏

oh, this is a toughie...

Subscribe Learn to build production-ready serverless applications on AWS

If you liked this, then you might also enjoy the tips and tutorials I publish every week about AWS and serverless.

Subscribe to my free newsletter and level up your AWS game: theburningmonk.com/subscribe

You can also put CloudFront in front of your API and cache and handle these preflight requests at a lower cost. This doesn’t eliminate preflight request-related charges entirely, but it goes a long way to minimize it.

But for personal projects or side hustles, where margins are tight, cutting these unnecessary costs can make a meaningful difference.

Of course, subdomains aren’t inherently bad, and many organizations prefer them to organize multiple APIs and environments. And maybe even let teams have their own subdomains and allow them to be more autonomous.

Now, here’s the thing that surprises most folks.

Even if your API is hosted on a subdomain, e.g. api.example.com, the browser still sees it as a cross-origin request from example.com.

Moving the API to example.com/api will eliminate the need for preflight requests altogether.

Every time the browser makes a cross-origin request, it first makes a preflight request to make sure it can actually send the request.

Since API Gateway charges per request, you’re billed for both the preflight and the main request.

Stop wasting money on CORS preflight requests.

Here's a quick tip for reducing API Gateway costs. 👇