· 18 min read
Building Chat Memory That Still Works at Turn 900
Replaying the full chat history works at turn 3. At turn 900 it is why your bill is high and your assistant is wrong.
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ai engineeringsystem design
Featured writing
Writing on AI engineering
Prompt engineering, system design, and building AI products that hold up past the demo. Cross-posted from Substack.
· 11 min read
Your System Already Has an Overload Strategy. You Just Didn’t Pick It.
A plain-English guide to backpressure, the most important concept nobody explains to junior engineers.
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distributed systemssystem design
· 6 min read
The Cost of Certainty in Distributed Systems
Most distributed systems don’t eliminate uncertainty — they just hide it.
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distributed systemssystem design
· 11 min read
How LinkedIn Could Feed You a Feed in Under 200ms (An Essay on Scale)
A quick note before we start: this is not a description of LinkedIn’s actual architecture.
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system design
· 6 min read
The Math Behind Your Feed’s Order (And What It Says About the Product)
Every social feed you scroll runs a scoring function on every post, in real time, before you ever see it.
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ai engineeringsystem design
· 11 min read
The 8 Constraints You Need Before You Draw a Single Box
“Design Twitter.”
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system design
· 2 min read
AI Engineering Is Real Work. That’s Exactly Why It Won’t Stay a Category.
Last weekend I spoke at CodeCon Summit. The talk was called “O Guia do Mochileiro da Engenharia de IA” — the hitchhiker’s guide to AI engineering — and the premise was ambitious: walk through 42 concepts anyone entering this field needs to understand today, in one session, for a room of over 300 engineers.
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ai engineeringsoftware engineering
· 4 min read
Software Engineers Are Becoming Product Engineers, Whether They Like It Or Not
Writing code fast stopped being a differentiator.
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product tasteproduct engineeringsoftware engineering
· 8 min read
The Interview Question That Actually Tests Seniority (And It’s Not About the Algorithm)
“You have a 20GB CSV.
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system design
· 6 min read
Lock, check, or reserve: the concurrency decision nobody teaches
Somewhere right now, a transaction is holding a lock open while it waits on a payment gateway to respond.
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concurrencysystem designlocking
· 5 min read
Your engineers are already using AI agents. You just don’t know how.
Fragmented adoption feels like progress.
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sdlcsoftware engineering
· 5 min read
The Hidden Cost Curve of 'Go Horse' Code
Every shortcut in engineering is a loan — and the interest rate is decided long before you know you’re paying it.
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software engineering
· 5 min read
The Hidden Cost of Chatty I/O
Every network call has a fixed tax.
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system design
· 10 min read
I asked 7 definitions of good code to judge the same function. they disagreed.
There is no universal standard for good code.
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clean codegood codearchitecture
· 8 min read
Before You Scale: What Chapter 1 of Designing Data-Intensive Applications Actually Teaches You
Everyone cites Designing Data-Intensive Applications. It’s on the reading list of every serious engineering team. Engineers drop it in interviews. CTOs reference it in system design discussions. But most people read it once, nod along, and move on without internalizing what the first chapter is actually saying.
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system design
· 5 min read
MCP + Skills: The New Interface for Engineering Work
There’s a type of cognitive overhead that engineers have normalized so completely they stopped noticing it.
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ai engineeringharness engineering
· 4 min read
Streaming in LLM Agents Isn’t Just a UX Feature. It’s an Architecture Decision.
Most teams add streaming to their AI products because it feels faster.
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ai engineeringsystem design
· 7 min read
Building Internal Chatbots That Actually Work
Every company I’ve worked with has the same problem dressed in different clothes.
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ragai engineeringsystem design
· 12 min read
The Unit Economics of AI Products
Traditional SaaS has a comforting property: infrastructure costs are largely fixed.
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ai engineering
· 18 min read
Caveman Prompting: I Tested the Claim. The Real Finding Is Somewhere Else.
There’s an idea that circulates in AI engineering circles called “caveman prompting.” The premise: write your instructions in stripped-down, telegraphic English — almost no grammar, no courtesy, just the bare intent — and the model will still deliver.
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prompt engineeringai engineering