Gonçalo Pereira

A 45k-line C++ engine for the Dune board game: a phase state machine, an event bus, card and deck systems, and pluggable interaction adapters for TTY, scripted and recorded play. Godot front-end planned.

Reimplementations of ping and traceroute using raw sockets and handcrafted ICMP packets — TTL control, checksum computation and round-trip timing without libc abstractions.

A thread-safe drop-in replacement for malloc, free, realloc and calloc. Pre-allocated TINY/SMALL/LARGE zones over mmap, mutex-guarded metadata, and debug tooling that dumps the live allocation map with a hexdump.

Core libc functions rewritten in x86-64 assembly, working directly with the System V calling convention, registers and syscalls.

A POSIX-style shell with pipes, redirections, built-ins, environment handling and signal management — tokeniser and AST-based execution over fork/exec.

A reimplementation of ls — directory traversal, stat-based metadata, permission formatting and sort ordering.

A raycasting engine in the Wolfenstein 3D tradition — real-time rendering, texture mapping and per-column projection maths.

An IRCv3 server in C++ serving many concurrent clients from a single poll() loop over non-blocking sockets — channels, operator modes, and a companion bot. Tested against real clients such as HexChat.

An RFC 6238 TOTP generator in Go. Keys are sealed with PBKDF2 (100k iterations) and AES-256-GCM; it also emits enrolment QR codes and serves a self-refreshing web UI. Later ported to Python as a second pass.

An ARP cache-poisoning tool in Go that puts itself between two hosts on a LAN and reconstructs plaintext FTP exchanges from the redirected traffic — a hands-on study of why unencrypted protocols fail.

A recursive web scraper paired with an EXIF metadata inspector — reconnaissance tooling and a practical look at what images leak.

A Tor hidden service deployed in a container — onion routing, key-based SSH access and the anatomy of anonymous network communication.

Binary reverse engineering — disassembly, control-flow reconstruction and recovering algorithms from compiled code without source.

An intensive security bootcamp covering vulnerability analysis, exploitation techniques and defensive strategy across a series of graded challenges.

A voting-pool web application with a Go backend and a React front-end — real-time results, user management, and CI covering vet, tests and image builds.

A multi-container infrastructure built from scratch — hand-written Dockerfiles for NGINX, WordPress and MariaDB, wired together with Docker Compose, volumes and an internal network.

Kubernetes from the ground up — K3s clusters provisioned with Vagrant, moving toward K3d and GitOps-style continuous deployment.

A real-time multiplayer Pong platform on a Django backend — WebSocket gameplay, OAuth2 and JWT authentication, live chat and a containerised deployment.