Software Engineer

Leo Spegel

Curious about systems.
Focused on building them.

I enjoy understanding how software works beneath the surface — from backend architecture and Android development to cybersecurity, AI, and modern cloud systems. I'm driven by curiosity and learn best by building things.

Always learning • Always building • Always asking why

Current Direction

Building secure, scalable systems

I’m especially interested in backend development, system design, cybersecurity, cloud infrastructure, and how AI/data-driven systems can be built responsibly.

Java Kotlin Spring Boot Android Docker Linux Security AI

Who I Am

I don’t just want code to work. I want to understand why it works.

One of the first projects that really pulled me into software development wasn't a school assignment — it was an idea a friend and I had while playing Diablo II. We wondered if we could combine computer vision with automation to create a bot that could understand what was happening on screen.

Working on the movement logic, keyboard automation, and preparing training data for a YOLOv5 model gave me my first experience with AI, software engineering, and collaborative problem-solving. More importantly, it sparked a curiosity that has stayed with me ever since.

Looking back, I don't think that project was really about building a game bot. It was about discovering that software could solve interesting problems. Since then I've been driven by the same curiosity — understanding how systems work, why they work, and how different technologies come together to build something larger than the individual pieces.

What Drives Me

The things I keep coming back to

Understanding Systems

I enjoy seeing how different parts of a system connect — from frontend flows and APIs to backend logic, data, infrastructure, and security.

Learning by Building

I learn best by creating projects, testing ideas, breaking things, fixing them, and turning concepts into working software.

Security Mindset

My interest in cybersecurity has made me think more about secure APIs, access control, WAFs, OWASP risks, data protection, and responsible systems.

Continuous Learning

I like working in areas where there is always more to understand: backend engineering, Android, cloud, AI, architecture, and security.

Professional Experience

Learning in real-world environments

Android Developer Intern

Truecaller | Stockholm | Search Team

2025–2026
  • Worked in a production Android environment with Java and Kotlin.
  • Used MVVM, Clean Architecture, Jetpack Compose, and legacy XML.
  • Contributed during migration from Java/XML to Kotlin and Compose.
  • Debugged issues in a complex codebase with many connected components.
  • Participated in agile workflows, sprint planning, and code reviews.
  • Wrote and maintained unit tests using JUnit, Mockito, and MockK.

Department Manager / Store Associate

Willys

2014–Present

Responsible for department operations, planning, ordering, inventory, and problem-solving in a high-paced environment. This role has helped me build responsibility, structure, communication, and leadership.

Sales Representative

Centurion

2013–2014

Customer-facing role focused on communication, understanding needs, and solution-based selling.

Education

Education & Continuous Learning

Fullstack Development Program

FöretagsUniversitetet

2024–2026

Java, Spring Boot, Node.js, React, Angular, databases, REST APIs, secure development, DevOps, agile workflows, and fullstack projects.

Cybersecurity

FöretagsUniversitetet

2026

Network security, cyber kill chain, DevSecOps, vulnerability management, incident response, forensics, log analysis, and SCADA/ICS systems.

Data Protection, AI & Compliance

FöretagsUniversitetet

2026

GDPR, AI Act, privacy by design, AI ethics, compliance, risk management, and regulatory frameworks.

Skills

Tools I enjoy working with

Languages

Java, Kotlin, JavaScript, TypeScript, Python

Backend

Spring Boot, Node.js, Express, REST APIs, SQL, NoSQL

Frontend

React, Angular, HTML, CSS, JavaScript

Android

Jetpack Compose, XML, MVVM, Clean Architecture

DevOps

Docker, Linux, Git, CI/CD, AWS/GCP basics

Security

OWASP Top 10, JWT, RBAC, IAM, MFA, Secure API Design, WAF

Data & AI

AI governance, data protection, YOLOv5 experiments, GDPR, AI Act

Ways of Working

Agile, code reviews, testing, documentation, teamwork

Learning Together

Some of my best learning happens with other people.

Programming has never been just an individual activity for me. Some of the biggest breakthroughs have come from discussing ideas, exploring different solutions, and building projects together with friends and classmates.

Alongside my studies, I've been involved in the student council where I helped represent students and contribute ideas for improving the education. It taught me the importance of communication, responsibility, and listening to different perspectives.

I also started regular programming meetups with friends and classmates where we choose a theme, build small projects, and present our solutions to each other. What began as a casual way to learn has become one of my favorite ways to discover new technologies and challenge the way I think about software.

Let’s Connect

Let’s build something interesting.

Whether you want to talk about backend development, Android, cybersecurity, AI, or simply enjoy discussing how systems work, I'd love to hear from you.