David Behroozi
@rootothez.bsky.social
📤 617
📥 124
📝 304
Solo developer. Doing the impossible; faster.
https://speedrun.cc
AWS Community Builder.
The baby Steller's Jay is out barnstorming.
14 days ago
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Since everyone forgot how to write json by hand after the AI meteor strike of 2021 caused permanent darkmode, Speedrun 1.55 can now generate the necessary json config to wire your GitHub markdown to your AWS accounts with just your Identity Center start url.
github.com/No-Backspace...
24 days ago
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Journeyed to Wisconsin for some cheese therapy. Shullsburg Creamery's muenster melts different and cures ails.
about 1 month ago
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Finally maxed my ESM score.
about 2 months ago
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Good news! That 50ms coldstart latency regression that appeared when using the AWS Javascript V3 SDK on Lambda with Node >= 22 is now fixed.
github.com/aws/aws-sdk-...
Update your dependency to v3.1011 to get back in the fast lane. Comparing my patched v3.1006 to v3.1011 shows no delta.
2 months ago
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I ran my benchmark overnight to confirm there wasn't much improvement when turning on NODE_COMPILE_CACHE with Lambda Coldstarts. It's less than a 10ms improvement. There may be benefits with larger packages but for my setup (200K zip file) it isn't worth the trouble.
2 months ago
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I experimented today with enabling NODE_COMPILE_CACHE to see if it would make Lambda coldstarts faster. I was able to create a .zip file with the cache from a previous run. I verified node used the cache successfully with NODE_DEBUG_NATIVE="COMPILE_CACHE". It didn't reduce the coldstart time 🫠.
2 months ago
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LLRT v.8.1-beta has the fastest p50 InitDuration by 130ms. But if you measure E2E time from the client (what you should measure), it narrows to 79ms over AwsLite and 118ms over a modified AWS v3 JavaScript client on Node 24. This is likely due to the size of the LLRT binary being ~5MB.
2 months ago
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Anecdotally I've noticed Lambda nodejs coldstart latencies trending down but visualizing the improvement using the daily maxday numbers is hard:
maxday.github.io/lambda-perf/
I pulled the data and graphed it. Indeed, it's showing a 20-30ms improvement since November last year. Here's nodejs on arm.
2 months ago
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Getting the client ip address when using a Lambda Function Url generally works, but sometimes you get a spoofed one. In this article I cover how to workaround the undocumented mangling Lambda does to the `x-forwarded-for` header.
speedrun.nobackspacecrew.com/blog/2026/03...
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Obtaining caller ip address with Lambda FURLs - Speedrun
When x-forwarded-for lies
https://speedrun.nobackspacecrew.com/blog/2026/03/06/obtaining-caller-ip-address-with-lambda-furls.html#further-reading
2 months ago
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I discovered that if you use Lambda furls, the x-forwarded-for header is truncated to the leftmost value. If you front your furl with CloudFront, the ip in that header is spoofable. CloudFront appends the viewer ip to the value of x-forwarded-for. Workaround is:
github.com/aws-samples/...
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https://github.com/aws-samples/amazon-cloudfront-functions/blob/main/add-true-client-ip-header/index.js
3 months ago
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TIL I was still using http 1.1 to connect to my api which supported http3. Because http3 is still kind of broken in Firefox:
bugzilla.mozilla.org/show_bug.cgi...
and when you enable http3 in CloudFront using the CDK, it disables http2.
github.com/aws/aws-cdk/...
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2012553 - Firefox reliably negotiates HTTP/3 on 0 of 7 H3-capable sites on cold navigations (1 with DoH), while Chrome negotiates 7 of 7
NEW (nobody) in Core - Networking: HTTP. Last updated 2026-02-12.
https://bugzilla.mozilla.org/show_bug.cgi?id=2012553
3 months ago
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TIL you can get edge location in your CloudFront Functions.
docs.aws.amazon.com/AmazonCloudF...
3 months ago
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Hello darkness my old friend. I just updated to JQuery 4.0.0. Ready for 10 more years of $.
3 months ago
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PSA: There is a performance penalty when using named exports with ESM import vs. require on built-in node modules. This is why the AWS JavaScript V3 SDK has 50 ms slower Lambda coldstarts on Node 22+. Some notes here:
github.com/aws/aws-sdk-...
3 months ago
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Look, the plating and bread choice leaves room for improvement. But the flavor of my latest Persian-American cuisine; the sumac avocado toast slaps.
3 months ago
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After many exasperated console.log's I looked at the docs and discovered CloudFront functions don't run on responses with a status code >= 400. So my edge metrics only work on successful requests.
docs.aws.amazon.com/AmazonCloudF...
4 months ago
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Seeing some Dr. Suess bird in my latte this morning
4 months ago
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Ode to 2025. My pithy year in review. "May your 2026 involve some hand-written code and may it compile without errors."
speedrun.nobackspacecrew.com/blog/2026/01...
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2025 year in review - Speedrun
A fun look back on 2025
https://speedrun.nobackspacecrew.com/blog/2026/01/09/2025-year-in-review.html
4 months ago
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It's important to know someone in London. Eventually you'll need their help unsubscribing from Domino's UK marketing because the US is region blocked 😂.
4 months ago
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I swear AWS had some hero image on a docs site with this hotel carpet vibe once.
4 months ago
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Took a quick break from the curiosities of London to have a curry and a pint with Cloudflare's lord of logs and corduroy trousers
@ankcorn.dev
5 months ago
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A short story: 1. This showed up in the group chat 2. Replied with "Nicolas UNCAGED?" 3. Checked El goog to see if this pun was a world first 4. Alas
5 months ago
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Boris is still at it and still gets it. Logging properly is on you and rn your:
loggingsucks.com
add a skeleton here at some point
5 months ago
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The answer to why account based endpoints didn't reduce the blast radius of the DynamoDb Oct event was in DAT458. They don't point to cells yet, they still point to the regional endpoint🤦♂️.
youtu.be/YZUNNzLDWb8?...
add a skeleton here at some point
5 months ago
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I'm relishing using AI to click the bait for me.
5 months ago
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Clearly the old spice product marketing team was cut from the same cloth as me.
5 months ago
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This is very clever. Tom Larkworthy shows how to unaggregate CloudWatch metrics and some neat insights you get when you do:
observablehq.com/@tomlarkwort...
5 months ago
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Not sure I want my company outlined in chalk but safety in numbers at re:invent.
6 months ago
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I got Cloudflare Workers to act as an API Gateway and do granular throttling for a Lambda using
github.com/mhart/aws4fe...
1. I really like 𝚠𝚛𝚊𝚗𝚐𝚕𝚎𝚛 𝚍𝚎𝚟 to rapidly iterate 2. Cloudflare Workers are way better than CloudFront Functions
6 months ago
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There is not a deep enough place in hell for the continue reading button, the random playing video and the slop ads below the fold.
6 months ago
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Been messing with Cloudflare Workers after reading
@boristane.bsky.social
boristane.com/blog/what-ar...
Delighted to find how easy it is to implement granular api throttling:
developers.cloudflare.com/workers/runt...
Something I've wished I could do with Cloudfront Functions for some time.
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Boris Tane
Notes from 2 years of building with Cloudflare Durable Objects
https://boristane.com/blog/what-are-cloudflare-durable-objects/
6 months ago
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If you use Discord and don't want everyone to know what you are doing, turn this off: Settings -> Activity Privacy.
6 months ago
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Armored up and went ball hunting in the blackberries. Lightly shredded, but I can now play lacrosse, rugby, soccer, tee-ball and ultimate.
6 months ago
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The Cognito M2M pricing was repealed! Now it's $2.25/1000 tokens regardless of number of clients.
aws.amazon.com/about-aws/wh...
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Amazon Cognito removes Machine-to-Machine app client price dimension - AWS
Discover more about what's new at AWS with Amazon Cognito removes Machine-to-Machine app client price dimension
https://aws.amazon.com/about-aws/whats-new/2025/11/amazon-cognito-removes-machine-machine-app-client-price-dimension/
7 months ago
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I've started tagging my CDK projects so I can find them on disk when I inevitably need to upgrade the Lambda runtime.
7 months ago
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They briefly mention the account based endpoints in the writeup:
aws.amazon.com/message/1019...
But my question remains, were those endpoints also impacted? Were the teams that couldn't get to dynamo not using the account based endpoints?
add a skeleton here at some point
7 months ago
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Ha! Something good came of the AWS incident Monday. I purchased a day pass to SlingTV to watch the Mariners play only to find I bought the wrong color (bought orange instead of blue which had the game). There aren't refunds on day passes, but due to the outage, they refunded me. I'll allow it!
7 months ago
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When the dust settles with the DynamoDB DNS issue, i'd be interested in understanding if it impacted the main DNS only:
dynamodb.us-east-1.amazonaws.com
or also the account id based DNS: <accountid>.ddb.us-east-1.amazonaws.com? The account id DNS should have reduced the blast radius in theory.
7 months ago
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One nice thing about cycling is the tool roadkill. This is the second pair of lock-jaw pliers I've found in the street.
7 months ago
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I wrote about migrating my API from Node 22 to LLRT and the dragons I battled on the way.
speedrun.nobackspacecrew.com/blog/2025/10...
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Migrating to LLRT - Speedrun
So long Node 22
https://speedrun.nobackspacecrew.com/blog/2025/10/16/migrating-to-llrt.html
7 months ago
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We did it fam. I successfully got my api working on LLRT. I had to switch to hono, drop jose, and modify some request parsing for form data, but IT WORKS! Seeing 188 ms Init Duration vs. 375 ms for Node 22. Warm requests with AWS service calls are like 60ms faster too.
7 months ago
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These aren't called spaces because tabs are better. This conversation is complete.
7 months ago
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Lambda perf hasn't been working since September 15th:
maxday.github.io/lambda-perf/
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Lambda Cold Starts benchmark | maxday
Visualize 10 Cold Starts for each runtime, updated daily
https://maxday.github.io/lambda-perf/
8 months ago
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It appears I was using `@initDuration+@billedDuration` and not `@initDuration + @duration` artificially inflating the baseline to 144ms from ~78ms. The delta between making a service call to STS from init vs. the handler is close to nothing when using llrt.
add a skeleton here at some point
8 months ago
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@jason.energy
was a multimodal mc at
#cascadiajs
He ranged from concert in the park pose to Carole Baskin leopard print. Good times!
8 months ago
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The next version of LLRT supports calling AWS services in init so you can utilize the extra CPU power. In testing, the initDuration+duration went from p50 of 144 ms to 76 ms! However, the E2E duration (from the client) stayed the same p50 of 268 ms vs p50 of 266 ms. This makes no sense to me.
8 months ago
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My garbage disposal kept failing due to low voltage at the switch (36 volts instead of 120). Today after it failed for the third time and my normal voodoo didn't work, I bought a new switch. The culprit was smoked sugar ants in the contact.
8 months ago
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Got my api running on llrt! They patched the iam client issue. Init Duration vs Node 22 went from 375 ms to 114 ms (3.3x improvement) and normal invokes went from 181 ms to 81 ms (2.2x improvement). All with much less memory; in Node I allocated 832 MB vs 256 MB for llrt.
add a skeleton here at some point
8 months ago
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PSA, the npm packages `debug` and `chalk` got compromised.
www.aikido.dev/blog/npm-deb...
This hacker news comment has a ripgrep command to make sure you don't have it:
news.ycombinator.com/item?id=4517...
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npm debug and chalk packages compromised
The popular packages debug and chalk on npm have been compromised with malicious code
https://www.aikido.dev/blog/npm-debug-and-chalk-packages-compromised
8 months ago
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