Performance
The Web Font That Made Your Page Invisible for Two Seconds
With font display block, the browser renders nothing where the text should be until the font arrives, and on a slow network the page is a blank skeleton…
Rohit Bhadani
I write about why software breaks and how people figure it out. Founder of Krova Cloud, building isolated microVMs on our own hypervisor. Years of Shopify theme work and shared hosting before that. If I have not reproduced it, I do not publish it.
DevOps
The Ingress Annotation That Silently Changed Your Timeout
The app's timeouts were tested and correct, and the 504s kept coming, because the ingress controller has its own defaults for body size, buffering and read…
Tooling
Ten bpftrace One Liners That Replace a Week of Guessing
Latency without CPU, stalls without errors, syscalls nobody counted. The kernel already observes all of it, and bpftrace turns the observation into a one…
DevOps
Six Months of Running MicroVMs in Production
What broke, what surprised me, and what I would tell someone considering Firecracker for their own platform.
Code Review
The Pull Request That Logged an Email Address at Debug Level
Debug logging the full request body is one flag flip from production, and the request body is where the email, the token and the card reference live.
Opinion
Technical Debt Is the Wrong Metaphor
Debt implies a known principal, a rate and a repayment plan. Most of what we call technical debt is none of those.
Deep Dive
Vacuum, Dead Tuples and the Wraparound Shutdown Nobody Plans For
MVCC gives every transaction an id and keeps old row versions until vacuum says they are dead to everyone. If vacuum falls behind for long enough, the id…
Bug Hunt
The Request That Failed Only When the Input Contained a Comma
Search worked for every input except inputs with a comma, which 404'd. The comma is legal in a URI path, but a router in the middle split on it anyway, and…
Error Autopsy
relation does not exist for a Table That Is Definitely There
The query fails with relation does not exist while the table sits in the schema browser a click away. The table never moved.
Shopify
The App Embed Block That Moved to the Top of Every Page
After a theme update, an app's script ran before the theme's and broke it. App embed blocks live in the theme's JSON, not in the app, so a theme update…
Security
What Your Incrementing Order IDs Tell Your Competitors
Sequential order IDs are a public counter of your volume, and they make every authorisation bug trivially exploitable.
Performance
Two Hundred Redis Calls, and Every One Was a Round Trip
Each Redis command took a tenth of a millisecond to execute and a full round trip to deliver, and two hundred of them in a loop made the request slow while…