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{
"name" : "Djiby Sow Rebollo",
"role" : "Software Engineering Student → Systems & Security Engineer",
"university" : "Edinburgh Napier University (BSc Software Development, Sep 2026)",
"location" : "Edinburgh , Scotland",
"focus" : ["Systems", "Backend ", "Security ", "AI/ML engineering applied to <----S.B.S"],
"building" : ["PulseDB, database engine from scratch", "Own shell", "AI coding agent"],
"learning" : ["Python at depth", "AI/ML engineering", "Applied cryptography"],
"principle" : "Understand the machine. Don't just use the tools, build them."
}The project that started with a question: how does a database actually work?
Building a functional database engine without external libraries — storage management, B-tree indexing, a query parser, and execution engine from first principles. Not a tutorial. Not a clone. A deliberate attempt to understand what happens below the ORM.
What I've learned that no course teaches:
- Why page sizes matter for I/O performance
- How indexes trade write speed for read speed at the byte level
- What "ACID" actually costs in implementation terms
C Java Systems Design Storage Engines Data Structures
Not "hello world" with a database. An actual backend.
JWT authentication, role-based access control, PostgreSQL, Docker, full CI/CD pipeline via GitHub Actions, and complete test coverage. Built from scratch in Java 21 + Spring Boot, designed to be deployed, not just demoed.
Java Spring Boot PostgreSQL Docker Maven JWT GitHub Actions
42 PHPUnit tests. CSRF protection. Rate limiting. Certificate generation. The works.
A full-stack web platform built in PHP with session management, role-based admin dashboard, REST API, and a proper security layer. The kind of project that teaches you what "production-ready" actually means.
PHP MySQL Bootstrap PHPUnit Security REST API
Natural language search. No CSS frameworks. Deployed.
Nursery finder with AI-driven natural language search, filtering by area, age range, Ofsted rating, and price. Built with Next.js 15, React 19, and TypeScript — without reaching for Bootstrap or Tailwind. Live at nvvri.vercel.app.
TypeScript Next.js React AI Vercel
If you can build it, you understand it.
A running series of systems-level reimplementations:
| Tool | Status | What it taught me |
|---|---|---|
| Group Chat (Sockets) | ✅ Complete | TCP, multi-client handling, concurrency |
| Own Shell | 🔄 In progress | Process forking, pipes, signals, PATH resolution |
| AI Coding Agent | 🔄 In progress | LLM APIs, tool calling, agent loops |
| PulseDB | ✅ Complete | In-memory data structures, serialisation, persistence |
| Git internals | 📋 Planned | Content-addressable storage, DAGs, hashing |
| Compiler (subset) | 📋 Planned | Lexing, parsing, AST, code generation |
C Java Python Networking Protocols Systems
Offensive skills make better defensive engineers.
Hands-on security research across penetration testing, log analysis, CVE research, and hardening. Documenting findings and write-ups as I progress through TryHackMe and Hack The Box tracks.
Parrot OS Linux Pen Testing CVE Analysis Hardening
[2026] ████████████░░░░░░░░ Python mastery — OOP, testing, packaging
[2026] ██████░░░░░░░░░░░░░░ AI/ML foundations — numpy, pandas, sklearn
[2026] ████████░░░░░░░░░░░░ Applied security — TryHackMe, PortSwigger
[2026] █████████████████░░░ Systems programming — memory, concurrency, I/O
The roadmap: strong systems foundations → production Python → ML engineering → DevSecOps. Everything connects. Security makes me a better engineer. Systems knowledge makes me a better security researcher. ML gives me a new set of tools to apply to both.
Languages
Backend & Frameworks
Web & Frontend
Databases
Testing
Build Tools
Infrastructure & DevOps
Security
I came into software engineering from an unusual direction — not from a computer science family or a bootcamp, but from figuring things out because I had to. That gives me something I think is genuinely useful: I am not afraid of not knowing something, because not knowing has always just been the starting point.
I build things from scratch not to reinvent wheels, but because you cannot truly understand a wheel until you have tried to build one. Every system I rebuild teaches me something no tutorial ever could.
Long term: DevSecOps and AI-driven security tooling. Right now: laying the kind of foundations that make those goals realistic.
If not me, who? If not now, when?
Working on something in backend systems, security tooling, or infrastructure engineering? Want to exchange ideas on systems design, applied security, or ML in security contexts?
