Lucas Sifoni

DtsBuddy and Pwmx, two libraries for runtime overlays and PWM channels from Elixir

DtsBuddy loads configfs device-tree overlays at runtime, Pwmx drives sysfs PWM channels

Care over time is the only software success metric now

This new profusion era made new software hard to trust

Wallace the 6 inch f/2.8 telescope, building it, and hiking with it

Hiking with Wallace, my 6" f/2.8 corrected dobsonian.

Hot-swappable LiveView components

What if your components could be contracts for runtime implementations, instead of concrete materialized components ?

Flood of tokens... a few doubts and comments about LLM codegen

A worm in my Erlang cluster, and adventures in microfluidics

Self-propagating code in a cluster allows to draw a map of this cluster from any node.

Filming flood fills with ink

Dripping ink on 3d printed graph traversals

34 days in an Elixir tunnel to refactor my SaaS without a rewrite

34 days of refactoring, from single-instance single-tenant to a multi-tenant cluster. How I fought the idea of a rewrite and used the elixir compiler and architecture linting to refactor Alzo layer by layer.

[Talk] Elixir-FR online Elixir meetup may 2026 - a modular monolith with hot code loading

Hot code loading for feature segregation in Elixir

Table ronde optique amateur francophone 2026 - recap

A look back at the first edition of the Table ronde optique amateur francophone, held online on March 4-5, 2026. Slides and videos are now published.

Table ronde optique amateur francophone 2026

I'm organizing a two-evening online event for French-speaking amateur opticians and telescope makers on March 4-5, 2026.

K2 was featured in Sky and Telescope

The magazine Sky and Telescope featured K2 in its Jan 2026 issue

2025 amateur optics / astronomy updates

What was worked on this year

The tiniest yet real telescope I've built

76/300 Pocket Dobson: a tiny yet real telescope that comes with you everywhere

Guest post @ AppSignal - Debugging in Elixir with Observer

Introduction to the Erlang Observer app, on the Appsignal blog

Code Introspection in Elixir for safely firing one-off scripts

How Elixir's runtime code discovery enables safe, discoverable, and UI-driven data cleaning scripts

Leveraging Elixir's hot code loading capabilities to modularize a monolithic app

How hot code loading solves client-specific engineering problems in my startup Alzo

The best 3d printable 6"f5 (150/750) portable travel dobsonian telescope as of today

My friend Raphaël produces a small yet mighty telescope.

Computed / reactive property flows in Elixir, not specificially for LiveView

Spreadsheet-like computed / reactive properties in Elixir with automatic dependency tracking. Framework-independent approach to computed properties.

Pointers to in-memory nested maps in Elixir and concurrent access patterns

Comparing five pointer implementation strategies for accessing nested data in Elixir - benchmarking closures, pattern matching, and inter-process access patterns

Computed / reactive properties in Liveview : a pure Elixir approach

How to implement computed / reactvive properties in Phoenix LiveView using pure functional patterns. Practical examples for managing state without dependency graphs.

[Talk] BEAMing online Elixir meetup march 2025 - hot code loading and language interop

Hot code loading and third party (node, java) interops from Elixir

Elixir from elixir

Using dynamic nodes to protect your BEAM from dangerous NIFs - a practical approach to isolating risky C code while keeping your main application safe

Git Igor

The curious case of misspelled .gitignore files on GitHub - how common typos like .gitigore can lead to unwanted files being committed

Liveview + Elixir can be super boring

Peace in the midst of frontend hardships

EleusisT's 3D printable DIY 1:10 crayford reducer / fine focus knob

Fostering community around a simple yet truly needed project.

Variations on the "leverage language from elixir" pattern.

Three approaches to integrating other languages with Elixir - generating code, embedding foreign code, and building instruction sets for cross-language orchestration

2024 amateur optics / astronomy updates

What was worked on this year

[Talk] ElixirConf EU 24 — Let's write a toy language from scratch in Elixir

From zero to execution for Ovo, a toy programming language.

[Podcast] ElixirWizards S13E04 — Creating a Terrestrial Telescope using Nerves & LiveView

SmartLogic podcast interview about building a remote-controlled telescope with Elixir, Nerves, and LiveView - expanding on my Code BEAM EU 2023 presentation

What if LiveView gave DOM access to Elixir ?

Experimenting with direct DOM manipulation from Elixir - batched and sequential DOM operations without hooks for complex LiveView applications

Open XYZ platform for interferometry

3D printable XYZ platform with 40mm+ travel using only M4 hardware - tested design for Bath interferometers with coarse/fine motion capabilities

My one-day white-hat career

Finding and reporting a massive vulnerability just to be legally threatened

Distributed transcription with Whisper and Elixir

Building a distributed audio transcription system with Elixir nodes, Bumblebee, and Whisper - splitting work across multiple computers without system configuration

Absurd debug : why is the website DOSing Spotify ?

A detective story of 18k outbound requests per minute from a WordPress site to Spotify - tracing back to uncached oEmbed fields and bot traffic

From a fresh ubuntu 22.04 ARM VM to embedded Elixir with nerves_system_rpi3 & circuits_quickstart

Playing with HTML5 Canvas from Elixir

Creating a server-side drawing API for HTML5 Canvas - using Elixir to generate optimized JavaScript commands for a circular PONG game

A lightweight and easy to build 1.25" crayford focuser

Files & description to build a simple 3D printed crayford focuser

Habanero / vegetarian / basque pepper hot sauce

A nice hot sauce recipe

An (Elixir+Nerves)-powered Cloud ☁️ (1/2)

Creating an art installation that generates real clouds controlled by electromagnetic field sensors - built with Elixir, Nerves, and LiveView

Hello AtomVM — Elixir & Erlang on ESP32

Step-by-step guide to running Erlang and Elixir on ESP32 microcontrollers with AtomVM - from toolchain setup to Hello World examples

Hello Bumblebee. Hello, Whisper ! Run ML models from Elixir

Implementing OpenAI's Whisper speech-to-text model in Elixir with Bumblebee - a simple GenServer solution that replaces a complex Python microservices stack

Let's dive deep into Plug.Conn.send_file/5 - from Elixir to C syscalls

A code archaeology expedition from Elixir through Erlang to C - tracing how send_file uses the Linux kernel's zero-copy optimization for file transfers

[Talk] Code BEAM EU 23 - Prototyping a remote-controlled telescope with Elixir

Building a terrestrial telescope with Nerves, Rust NIFs, and Phoenix LiveView - full talk transcript with slides from Code BEAM EU 2023

Periodic averages with overflowing buckets in Elixir

Comparing circular buffer vs cascading bucket approaches for time-windowed data averages in Elixir for embedded systems

I would never allow users to upload PDFs in place of pictures

The evolution of a media upload system that started with JPG, PNG, and SVG but evolved to support PDFs with text selection - balancing technical purity with user workflows

Hosting a small language (Ovo2) from scratch in Elixir, pt 8<br/>The end : the Ovo Optimal Personal System (oops), with liveview

Creating a visual programming environment with Phoenix LiveView for Ovo2 - building the canonical 99 bottles of beer program using runner chaining and inter-program communication

Hosting a small language (Ovo2) from scratch in Elixir, pt 7<br/>Weird features, towards a global stateful machine

Going off the rails with Ovo2

Hosting a small language (Ovo2) from scratch in Elixir, pt 6<br/>Basic recursion : an environment is a process

Adding basic recursive abilities to ovo2

Hosting a small language (Ovo2) from scratch in Elixir, pt 5<br/>Evaluation

Evaluation of Ovo2 by walking its AST