What this is
A running log of the things I like tinkering with: writing code, electrical engineering, and mathematics. Some of it's handy, some of it's just me figuring things out in the open.
Background
My work spans multiple software layers, from consumer applications down to the systems beneath them. I began building native software for Apple platforms and the web, with a long run in user-interface engineering, then moved into low-level systems work and, more recently, applied machine learning. What ties it together is an interest in how things work down to the hardware they run on, which also keeps me close to electronics and the physics underneath.
Essays
Valentin Radu · 2026 ·
Valentin Radu · 2026 ·
Bookshelf
Les Misérables (Victor Hugo)
A book worth revisiting every decade. It reads differently each time.
The Feynman Lectures on Physics (Richard Feynman)
A fascinating account of how the world actually works, as much as we can figure it out anyway.
Friedrich Nietzsche
He looked at the world and wrote down what he actually saw, no filter. Hard to beat for sheer honesty.
Focus
Applied ML
Model serving, model fine tuning, agentic workflows, self-hosted deployment
Unix systems
Systems programming, lock-free concurrency, async I/O, profiling and performance
Applications
iOS and macOS, web, audio and graphics
Experience
Engineering lead
Kinoto · Porto · 2023–Present
Software developer
Berlin, London, Hamburg · 2016–2023
Application developer
Cluj, Romania · 2009–2016
Electrical CAD designer
Cluj, Romania · 2006–2009
Education
Computer Science · Philosophy
Awards
Google Android Developer Challenge
Trip Journal · Grand Prize · 2009
Dev log
Back to wires: Introduction
Updated Jun 2026A complete, ground-up course in electrical theory and code: how it's built, the shape of each lesson, and the ground it covers across eight areas from fundamentals to maintenance.
Show all 7 parts Hide parts
- 1. Back to wires: Introduction (above)
- 2. Back to wires: Direct current
- 3. Back to wires: DC circuit analysis
- 4. Back to wires: electric and magnetic fields
- 5. Back to wires: the electromagnetic field, light, and relativity
- 6. Back to wires: capacitors, inductors, and the circuits they shape
- 7. Back to wires: alternating current
Anthropic and the caravel problem
Jun 2026In 1500 a country of a million people invented the ship that opened the world, got rich beyond its size, and then lost everything to latecomers with deeper pockets. Frontier AI labs are sailing the same caravel. Why the model was never the moat, and the two narrow ways out.
npm install and pray. Axios and TanStack, 2026.
May 2026Two npm supply chain attacks in early 2026: the Axios compromise by Sapphire Sleet and the Mini Shai-Hulud worm by TeamPCP. What happened, how to check if you were hit, how to harden, and an honest look at how Pent would have mitigated these.
Vector search: The problem
Updated May 2026Why nearest neighbor search is easy in 1D, manageable in 2D, and falls apart in 768D. The first post in a series on vector search, working from the problem itself before the algorithms.
Show all 4 parts Hide parts
- 1. Vector search: The problem (above)
- 2. Vector search: Small worlds
- 3. Vector search: On disk
- 4. Vector search: Quantization
AI and technical writing
May 2026Almost every public article online is written with AI assistance now. So are the articles on this site. A note on how I write now, and why.
I built a compiler frontend with Claude's help. A retrospective.
Mar 2026A writeup of building formalang, a compiler frontend, with Claude in the loop. The actual workflow, what it cost in time and reading, where the agent helped most, and a final scorecard.
Self-hosting Devstral Small 2 on a 48 GB GPU
Dec 2025Deploy Mistral's Devstral Small 2 (24B coding model) with vLLM on a 48 GB workstation GPU or rented cloud instance, then connect it to OpenAI-compatible agentic clients (Cline, Continue, OpenCode).
The exponential thread: The puzzle
Updated Oct 2023Starting from a 3rd-grade equation and arguing that it is the entry point to the deepest unification in modern mathematics. e, ln, sin, cos, complex exponentials, matrices, and Lie groups all turn out to be the same object viewed from different angles. The first post in a nine-part series.
Show all 2 parts Hide parts
- 1. The exponential thread: The puzzle (above)
- 2. The exponential thread: Why e is natural
Show 2 more Show fewer
Rust for Swift devs: The type system
Updated Nov 2025Coming to Rust from Swift is a shorter transition than most assume. The first post in a series, starting with the type system: structs, enums, traits, generics, and the dyn/impl distinction.
Show all 6 parts Hide parts
- 1. Rust for Swift devs: The type system (above)
- 2. Rust for Swift devs: Error handling
- 3. Rust for Swift devs: Memory and ownership
- 4. Rust for Swift devs: Lifetimes
- 5. Rust for Swift devs: Concurrency
- 6. Rust for Swift devs: Tooling and interop
AWS Lambda + Rust
Mar 2019Deploying Rust on AWS Lambda in 2026: how the toolchain has changed since 2019, and what a minimal, idiomatic setup looks like today.