Firmware & Embedded Software Engineer

From game engines to rendering 3D inside a microcontroller.

I'm Andrés Ragot. I write modern C/C++ for embedded systems: ESP32, software graphics, LCD drivers, FreeRTOS, PSRAM and everything that lives between silicon and pixel.

See projects Get in touch

Embedded SW Engineer @ CipherBit — Grupo Oesía 📍 Madrid, Spain

// status● ONLINE

role      = "Embedded SW Engineer"
stack     = ["C", "C++17/20", "ESP-IDF"]
targets   = ["ESP32-P4", "ESP32-S3", "..."]
focus     = "firmware · graphics · rt"
side      = "esp32_3d_engine"
past_life = "Unreal, Unity, gameplay"

About

I started where most people who end up doing low-level work start: wanting to make video games. I studied engineering at INSA de Lyon in 2017 and then a Bachelor in Game Design & Development at UDIT in Madrid.

Along the way I got obsessed with the parts nobody sees: how bytes move, how a triangle gets rasterized, how much a dynamic allocation costs, why a frame takes 18 ms instead of 16. That obsession pushed me from the engine into the firmware.

Today I design and build firmware for connected embedded products: asynchronous event-driven architecture, PSRAM-aware memory strategies, modular hardware abstractions and product-driven firmware decisions. I still write software graphics on weekends — that's where both worlds meet.

Languages: Spanish, English, French

Now

Embedded Software Engineer

CipherBit — Grupo Oesía

May 2026 — present

Working on critical embedded systems for secure communications. I'll add concrete public details as soon as I can share them.

Experience

Embedded Software Engineer · CipherBit — Grupo Oesía May 2026 — present · Madrid, Spain

Firmware and embedded software inside the Oesía group, focused on communications and mission-critical systems.
Embedded Firmware Engineer · ORBIS Feb 2025 — May 2026 · Madrid, Spain

R&D on connected embedded products with focus on firmware architecture, low-level system design and modern C/C++. Redesigned critical parts of a legacy firmware stack to overcome flash, RAM and stability bottlenecks — improving runtime robustness and enabling richer product capabilities on constrained hardware. Async event-driven architecture, PSRAM-aware memory strategies, modular hardware abstractions and product-driven firmware decisions for reliability and maintainability.
Embedded Software Engineer · SingularThings Jan 2024 — Feb 2025 (intern from Nov 2023) · Madrid, Spain

Firmware development for custom embedded solutions: low-level programming, sensor and peripheral integration, early-stage wireless systems. Implemented embedded communication features and quickly took on increasing technical responsibility in a fast-moving startup environment.

Education

BSc Game Design & Development

UDIT — Madrid

2021 — 2025

Engineering studies

INSA de Lyon — France

2017 — 2021

Technical skills

Firmware & Embedded

Graphics & Real-time

Game Dev background

Tooling

Featured project

esp32_3d_engine

A software 3D rendering engine for ESP32 microcontrollers.

Renders full 3D scenes with lighting directly on the MCU — no GPU. Full software pipeline from vertex to framebuffer, custom scene graph, revolution/extrusion mesh generation, orbital camera, directional lighting, painter's algorithm and PSRAM allocator. Published as a component in the ESP Component Registry.

Software pipeline: transform → Sutherland-Hodgman clipping → projection → scanline rasterization → framebuffer.
Hierarchical scene graph with ID lookup and component tree (Transform, Mesh, Light).
Mesh generation by revolution and extrusion from 2D profiles.
Directional lighting (ambient + diffuse) in RGB565.
Double buffering, custom std::allocator placing large buffers in PSRAM.
Optional thread pool with std::jthread running scene/render on separate cores.
Pluggable LCD drivers: EK79007 (MIPI-DSI), ST7262 (RGB), ST7789 (SPI).
Supported targets: ESP32-P4 and ESP32-S3 (main testing), ESP32 / S2 / C3 via drivers.
C++ for 99% of the codebase. MIT license.

⚠ Real metrics measured on hardware. Average over 1000+ frames per configuration.

GitHub repo Doxygen docs ESP Component Registry

// architectureesp32_3d_engine

+----------------------------------+
|           app_main()             |
+---------+------------------------+
| Scene   |       Renderer         |
| +-----+ |  +--------+ +--------+ |
| |Node | |  | Camera | |Rasteriz| |
| | Mesh| |  | view   | | clip/  | |
| |  ...| |  | proj   | | fill   | |
| +-----+ |  +--------+ +---+----+ |
|         |                |       |
|         |        +-------v----+  |
|         |        |FrameBuffer |  |
|         |        |double-buf  |  |
|         |        +-------+----+  |
|         |                |       |
|         |        +-------v----+  |
|         |        | DriverLCD  |  |
|         |        |EK79007 /   |  |
|         |        |ST7262 /    |  |
|         |        |ST7789      |  |
|         |        +------------+  |
+----------------------------------+

C++17/20ESP-IDFESP32-P4/S3GLMCMakeKconfigPSRAMstd::jthread

REAL BENCHMARKS

01 · Baseline

Initial pipeline: single CPU, linear rasterization, no polygon sorting.

MCU	Meshes	FPS	Free heap
ESP32-P4	10	5.87	27.8 MB
ESP32-S3	10	9.09	8.0 MB
ESP32-P4	6	6.69	27.8 MB
ESP32-S3	6	10.22	8.0 MB
ESP32-P4	1	10.13	27.9 MB
ESP32-S3	1	17.27	8.0 MB

02 · Optimized meshes

Reduced triangle count, precomputed normals. Same pipeline as baseline.

MCU	Meshes	FPS	Free heap
ESP32-P4	10	6.71 +14%	27.8 MB
ESP32-S3	10	9.68 +6%	8.0 MB
ESP32-P4	6	7.44 +11%	27.8 MB
ESP32-S3	6	10.80 +6%	8.0 MB
ESP32-P4	1	10.16	27.9 MB
ESP32-S3	1	17.54 +2%	8.0 MB

03 · Painter's algorithm

Polygons sorted by depth. Less overdraw, no Z-buffer.

MCU	Meshes	FPS	Free heap
ESP32-P4	10	12.89 +120%	30.3 MB
ESP32-S3	10	16.48 +81%	8.3 MB
ESP32-P4	6	14.39 +115%	30.3 MB
ESP32-S3	6	18.78 +84%	8.3 MB
ESP32-P4	1	18.36 +81%	30.4 MB
ESP32-S3	1	28.52 +65%	8.4 MB

04 · Parallel + painter

Scene on one core, render on the other via std::jthread. Double buffer in PSRAM.

MCU	Meshes	FPS	Free heap
ESP32-P4	10	13.16 +124%	30.3 MB
ESP32-S3	10	17.54 +93%	8.3 MB
ESP32-P4	6	14.35 +114%	30.3 MB
ESP32-S3	6	18.89 +85%	8.3 MB
ESP32-P4	1	18.57 +83%	30.3 MB
ESP32-S3	1	29.00 +68%	8.3 MB

Average over 1000+ frames per configuration. ESP32-P4 240 MHz / ESP32-S3 240 MHz, both with PSRAM.

Selected work

Things I've built. Filter by discipline.

games 2024

Tailless

3D roguelike in Unreal starring an axolotl.

Unreal Engine 5.4 · C++ · Gameplay framework

Itch.io ↗Team site ↗

games 2023

Insane Lake (Ranas Insanas)

Fighting genre flipped: frogs dodging falling logs.

Unity · C# · Gameplay

Itch.io ↗

games 2023

Hidalgo

Spanish-Belgian hackathon: games for education, culture and tourism.

Unreal Engine 5.2 · C++ / Blueprints

Build (Drive) ↗

games 2023

Misran Fighters

Beat 'em up obsessed with game feel.

Unity · C# · Beat 'em up

Itch.io ↗

games 2022

Unwritten Alliances

Tower defense in 10 weeks — my first serious Unity project.

Unity · C# · Tower defense

Itch.io ↗

games 2023

Jumping Yayo

Two weeks, three people, one rule: trigger an emotion.

Unity · C#

Itch.io ↗

games 2021

No Eyes To See

My first official game: a roguelike inspired by The Binding of Isaac.

Construct

Itch.io ↗

Mini-demo: software render

A wireframe cube rasterized in JavaScript with the same idea esp32_3d_engine uses: transform vertices, project, draw lines. No WebGL, no libraries.

FPS: 0 Frame: 00000

A wireframe cube rasterized in JavaScript with the same idea esp32_3d_engine uses: transform vertices, project, draw lines. No WebGL, no libraries.

"From gameplay systems to embedded graphics: same obsession, fewer resources."

Let's talk

If what I do is interesting to you, drop me a line. I reply to concrete things faster than to generic intros.

$ whoami
andres-ragot

$ cat about.txt
Embedded SW Engineer.
Madrid · ES/EN/FR.

$ echo $STATUS
ready to talk firmware.