Principal Engineer · 16+ years
Helping engineers take LLM and agent systems from demo to production.
Architecture, evaluations, observability, failure handling, cost and latency: the parts a demo never has to answer for.
Or go deeper: the live cohort ↗
Make Staff When Implementation Is No Longer Scarce
Implementation got cheap. What you are promoted for now is judgement, owned in writing.
Tue, 1 Sept · 6:30pm London · 30 minutes · Zoom
What engineers say
29+ engineers and colleagues, sharing what changed after we worked together.
“Ehsan is a great developer who brings a wealth of experience and skill. He is very self-motivated and can deliver any piece of work, regardless of complexity. Ehsan has a real passion for learning and sharing what he knows with everyone else in the team. He's a real asset to any organization”
“The session was amazing and so informative covering a lot of topics like reviewing linked profile, CV and GitHub profile. Thank you so much for your time, Gaz.”
“It was a great session with Ehsan. I really admired the way he made me understand about so many things. I got to learn a lot from him”
More ways to learn
- Self-paced coursesFive self-paced courses, $99 to $299, from clean code and system design to LLM and agent systems.Browse courses →
- 1:1 mentorshipCareer, system-design judgment, and the path from senior to staff and principal.See programs →
- Writing & podcastHundreds of deep-dives on architecture, plus the Breakpoint podcast.Read the latest →
- Persian coursesThe Farsi side of the site: eight video courses on JavaScript, React, Node and code quality, plus writing in Persian.Open the Persian site →
AI writes it now. Keep your hands in the code.
Ten minutes and one TypeScript problem, written from memory against hidden tests, on a schedule that brings each one back just before you would have forgotten it. Free, and no account needed to try one.
Latest writing
I Use AI Every Day: Why I Built a Place to Practise the Old Problems
I use AI every day, I enjoy it, and I am not going back. What it quietly took is the part of me that produces code from an empty file: the best practices I used to apply without thinking, and the problem solving underneath them. Why the existing practice sites did not fit, and what I built instead.
LLM Tracing vs Evals: Which One Tells You Why Your Agent Broke
Your agent gave a bad answer and you cannot say why. Tracing tells you what happened on one request. Evals tell you whether quality moved across many. They answer different questions, and if you only build one this quarter, build the one that makes the other actionable.
The Innovator's Dilemma: Why Doing Everything Right Gets You Killed
Clayton Christensen showed why good engineering teams build irrelevant products. The paradox of listening to your best customers, and how to stop ignoring the toy technologies that will eventually replace you.
Containers vs Cloudflare Computer: There Is Not Enough Compute for One Box Per Agent
Nearly every agent framework decided that one agent means one container. Cloudflare says there are not enough computers on earth for that to work, and has flipped it around: the agent lives in a tiny sandbox with a filesystem that stays behind, and a container is only borrowed when Linux is truly needed. Here is the argument in plain words, why Cloudflare made it, and where I would use it.
Graph Engineering: Every Edge You Draw Takes a Decision Away From the Model
Agent graphs are state machines with a new name on them. The engineering question is not what a node is, it is which routing decisions you take away from the model and which you leave to it. The rule I apply: only draw edges for decisions you can make better in advance than the model can at runtime.
When Your Data Is Really a Graph: Write the Recursive Query First
Some questions cannot be answered by adding one more join, because the number of joins depends on the data rather than on the query. That is the moment your data has become a graph. Here is how to tell, what a graph actually buys you, and the two costs nobody mentions until you are already paying them.
Popular this week
What other engineers have been reading in the last seven days.
oxlint vs ESLint: Why I Replaced ESLint with oxlint
Replaced ESLint with oxlint in a React TypeScript project and cut lint time from 12 seconds to under one. What I traded away and whether it was worth it.
Lefthook vs Husky: Why I Switched and Never Looked Back
Lefthook replaces Husky and lint-staged with a single Go binary, parallel hook execution, and built-in file filtering. Here is why I switched and kept going.
Using Vitest, MSW, and Faker in TypeScript
Three tools that changed how I write tests: Vitest for speed, MSW for API mocking, and Faker for realistic data. How to wire them together in TypeScript.
Everything Is Being Rewritten in Rust. Is It Time You Learned It?
The kernel dropped the experimental label, Cloudflare rewrote its proxy, and your JavaScript build is already Rust underneath. That is the case for learning it. The case against is that the most important TypeScript tool of the decade picked Go. Here is how I read the trade-off, and where I would still not leave TypeScript.
Situational Awareness: The Decade Ahead to AGI by Leopold Aschenbrenner
A short, simple review of Leopold Aschenbrenner essay. He says AI will reach human-level smarts around 2027. Here is what he gets right, what he gets wrong, and what it means for you.
Containers vs Cloudflare Computer: There Is Not Enough Compute for One Box Per Agent
Nearly every agent framework decided that one agent means one container. Cloudflare says there are not enough computers on earth for that to work, and has flipped it around: the agent lives in a tiny sandbox with a filesystem that stays behind, and a container is only borrowed when Linux is truly needed. Here is the argument in plain words, why Cloudflare made it, and where I would use it.
Where to start
The deep dives I'd point a senior engineer at first, grouped by topic.
SQL, from SELECT to subqueries
Worked SQLZoo solutions, joins, aggregates, GROUP BY vs HAVING, and subqueries — the queries interviewers actually ask.
9 deep dives · Start reading →
Database performance & scaling
Indexes, query optimisation, sharding, replication and normalization — how to make a database fast and keep it fast.
8 deep dives · Start reading →Modern TypeScript tooling
Why oxlint replaced ESLint, pnpm vs npm, Lefthook vs Husky, and the Rust/Go shift in the frontend toolchain.
6 deep dives · Start reading →
Data structures in TypeScript
Arrays, linked lists, stacks, queues, trees, tries, graphs, heaps and hash tables — implemented and explained in TypeScript.
12 deep dives · Start reading →
Sorting & searching algorithms
Insertion, selection, merge and quick sort, plus binary and substring search — the classic algorithms, step by step.
6 deep dives · Start reading →
Design systems in practice
What a design system really is (per Atlassian), how Dropbox and Netflix build theirs, and how to roll out an internal UI component library.
6 deep dives · Start reading →
Scaling & system architecture
Horizontal vs vertical scaling, capacity estimation, resilience patterns and the architecture principles behind systems that grow.
6 deep dives · Start reading →
X vs Y: engineering trade-offs
Head-to-head breakdowns — oxlint vs ESLint, REST vs GraphQL, SQL vs NoSQL, Svelte/Preact vs React — with the trade-offs that decide it.
12 deep dives · Start reading →