Low-Level Systems Developer | C / C++ / POSIX — building toward Defense & Aerospace Software Engineering Madrid, Spain • LinkedIn • Mail : higuitaruben@hotmail.com

Transitioning from a decade of hands-on mechanical and electromechanical engineering — automotive, high-performance marine propulsion, industrial assembly — into systems-level software development. Currently building deep C/C++/POSIX foundations through 42 Madrid's peer-reviewed curriculum while working professionally inside Spain's defense-industry technical documentation chain.

The combination is deliberate: fault isolation, electrical schematic interpretation, and hardware diagnostics from the mechanical side; deterministic memory management and POSIX systems programming from the software side.

+--------------------------------------------------------------------------+
| APPLICATION & DAEMON LAYER                                               |
| Custom network daemons, FSM protocol parsers, multithreaded engines      |
+--------------------------------------------------------------------------+
                              |
                              v  [Syscalls: socket, poll/epoll, fork, pipe]
+--------------------------------------------------------------------------+
| OS & POSIX RUNTIME ENVIRONMENT (POSIX.1-2017)                            |
| Process lifecycles (waitpid), signal safety, virtual memory, pthreads    |
+--------------------------------------------------------------------------+
                              |
                              v  [VFS, Kernel Buffers, Hardware Buses]
+--------------------------------------------------------------------------+
| PHYSICAL & HARDWARE INTERFACE LAYER                                      |
| Electronic diagnostics, bus communications, high-power electro-drive     |
+--------------------------------------------------------------------------+

Event-driven network service in C++98, no external runtime libraries. Single-threaded polling architecture (poll/epoll) for asynchronous client streams, with a finite-state-machine parser for chunked HTTP requests and isolated CGI subprocess dispatch. Result: Pass with bonus (42 Madrid, 18/09/2026). github.com/higrub89/webserv

Unix command execution runtime in C: process trees (fork, execve), file descriptor redirection (dup2), deterministic process lifecycle via waitpid, and POSIX-async-signal-safe signal trapping (SIGINT, SIGQUIT). github.com/higrub89/minishell

Multithreaded simulation resolving shared-resource contention under microsecond-level timing constraints, with mutex arbitration to eliminate deadlocks and starvation. github.com/higrub89/philosophers

Real-time software renderer in C, writing directly to raw framebuffers, using DDA grid traversal to minimize floating-point operations. github.com/higrub89/cub3d

• 42 Madrid (Fundación Telefónica) — Systems Software Engineering curriculum. Common Core: 87% validated (in progress).
• Formación Profesional — Desarrollo de Aplicaciones Multiplataforma (DAM), CIPFPD La Rioja — in progress, bridging toward a Bachelor's in Computer Engineering.
• Technical Authoring & Systems Documentation — Sonovision Ingenieros España (Defense & Aerospace engineering services provider). Authoring and validation of technical repair/maintenance manuals for the VPTL Renault program, including interpretation of electrical schematics and CAN-Bus networks for documentation accuracy.
• High-Performance Electro-Propulsion Certification — CAYAGO AG (Bad Salzuflen, Germany). Certified diagnostics and service on SEABOB F5 and F9 high-voltage electric-drive systems.
• Advanced Linux Professional Certification (IFCT066PO, 100h) — SEPE / Comunidad de Madrid. (confirm exact issuing training center before publishing)

1. Toolchain compliance    : gcc/g++ -Wall -Wextra -Werror -pedantic
2. Memory policy           : zero reachable/leaked bytes in persistent services
3. Concurrency invariants  : zero data races (TSan-verified), deterministic lock ordering