Jakub
Nenczak
Curious software engineer always eager to learn and grow.
About
I've always loved learning and pushing myself to improve. Even after starting full-time work, I continued studying at 42 Roma LUISS, and now I'm exploring another field at a different university
Featured Engineering Work
Distributed RAG Document
Synthesis Platform
A simple CDE with integrated document synthesis, RAG retrieval and template-based document generation.
- Engineered a containerized RAG backend utilizing LlamaIndex for document chunking and metadata extraction.
- Integrated Qdrant as a dedicated Rust-based vector database for high-dimensional, low-latency similarity search.
- Designed a decoupled storage layer with MinIO for raw object storage and a clear migration path to PostgreSQL for distributed write scaling.
High-Performance HTTP/1.1
Server (webserv)
As a group effort we built a fully RFC-compliant HTTP server from scratch to handle thousands of concurrent connections under strict memory constraints.
- Bypassed standard web frameworks to implement a custom event loop and HTTP request parser in C++.
- Engineered a single-threaded, non-blocking I/O architecture using
select()multiplexing, managing up to 1024 concurrent file descriptors. - Implemented robust state-machine logic to handle partial socket reads/writes (EAGAIN), CGI
via
fork(), and memory safety under stress.
OS-Level Concurrency:
The Dining Philosophers
Simulating distributed resource contention without triggering deadlocks, livelocks, or thread starvation.
- Solved the classic Dining Philosophers problem by strictly managing OS-level concurrency in C.
- Implemented fine-grained mutex locking on shared resources (forks and stdout) to prevent data races.
Minimalist UNIX Shell
(Minishell)
Implemented a shell from scratch demands correct lexing, parsing, process lifecycle management, and signal handling — all without a single global variable beyond signal state.
- Built a Bash-inspired shell in C handling pipes, I/O redirection (including heredoc and
append), and
environment variable expansion with
$?. - Implemented all builtins (
cd,export,unset,env,exit) and child process execution viafork()/execve(). - Managed
SIGINT/SIGQUITsignal handling correctly in both parent and child contexts with zero memory leaks.
Raycasting 3D Engine
(Cub3D)
Rendering a convincing 3D world from a flat 2D grid requires a mathematically precise ray-grid intersection algorithm, fish-eye correction, and per-column texture sampling — all within a tight pixel-buffer rendering loop.
- Implemented a DDA raycasting engine in C, casting one ray per vertical screen stripe against a 2D tile map.
- Applied perpendicular wall distance correction to eliminate fish-eye distortion, with directional texture mapping for N/S/E/W wall faces.
- Engineered a double-buffered pixel rendering loop via MiniLibX and a custom
.cubconfig parser with full validation.
Currently Building
CoreQ
Automated Quotation System · Manufacturing / SME
A production management and automated quoting system for SMEs in the manufacturing sector — migrating a legacy MySQL codebase to a modern PostgreSQL + FastAPI architecture. The core design shift is a "Bottom-Up" data model where machine operations are bound to specific parts, parts to quotes, and quotes to orders, eliminating floating operations that exist in a vacuum.
Key pillars include a Virtual Machine Park (digital twins with hourly rates and physical constraints), Material Digital Twins (density + live market pricing via cron jobs hitting LME APIs), and a Cascading Analytics layer with SQL views that automatically compute margins and client Whale Scores.
machines and materials tables in
SQLAlchemy; updating
technological calculators to use machine_id
over legacy category strings.machine_operators
permission matrix, APS
bottleneck detection.Experience
- Reverse-engineered undocumented legacy APIs through network traffic analysis, enabling seamless integration with existing systems and uncovering critical business logic.
- Designed and developed a mobile application to modernize and replace the legacy platform, delivering an improved user experience and streamlined workflows.
- Implemented the BLoC architectural pattern across the application and mentored team members on its principles, promoting maintainable, scalable, and testable code practices.
- Served as a consultant for a leading Italian telecommunications company, contributing as a Platform Engineer to enhance internal developer productivity and operational efficiency.
- Designed and developed internal tools to support platform workflows, streamline processes, and improve cross-team collaboration across engineering functions.
- Managed and optimized Kubernetes-based infrastructure, ensuring scalability, reliability, and efficient orchestration of enterprise-grade services.
E-commerce mobile application for a small local Polish premium clothing brand — handling product listings, cart, and checkout flows.
Mobile application for travellers — integrating Google Maps for location discovery, Supabase for real-time backend, cloud functions for server-side logic, and push notifications for user engagement.