Nikos Papatheodorou npapatheodorou

Scalable, secure, high-performance backend systems. ⚡🔒
🧠 JVM-first | 🛡️ Security-minded | 🚀 Performance-tuned

✨ Building resilient platforms where security and speed coexist.

✨ Snapshot

👤 Profile

I design and build JVM-first backend systems for modern web and mobile applications, treating scalability, security, and performance as first-class requirements.

North Star 🧭: reliability, security, and speed are features, not afterthoughts.

🎯 Focus Areas

🧠 JVM-first backend engineering in Java and Kotlin
⚙️ CI/CD pipeline architecture and delivery automation
📦 Containerized systems and infrastructure as code
🔐 Secure system design, blockchain, and identity research
👨‍🏫 Mentoring and technical knowledge-sharing

🧭 Career Snapshot

⚙️ DevOps Engineer (current)
🏢 Senior Developer at Ernst and Young (EY)
💻 Backend Developer (3.5 years)
🎓 MSc Researcher and Teaching Assistant

🧰 Toolbox

💻 Languages

🧩 Frameworks

⚙️ DevOps and Infra

📊 Data and Observability

📈 Metrics

🏆 Engineering Impact

Metric	Achievement
🚀 Deploy time reduction	95% faster
⬆️ System uptime	99.95% achieved
📦 Systems built	25+ production systems
🔒 Security incidents	Zero critical vulnerabilities
⚡ Performance improvement	94% response-time reduction
🏗️ Provisioning automation	97% faster infrastructure setup

🗺️ Focus Map

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mindmap
root((Backend))
JVM
Java
Kotlin
Spring
Quarkus
Performance
Profiling
Tuning
Reliability
Security
Blockchain
Identity
Cybersecurity
DevOps
CI/CD
IaC
Kubernetes
Data
Oracle
PostgreSQL
MySQL

🚀 Career Journey

graph LR
A[MSc Research - SSI and Blockchain - Teaching Assistant] --> B[Backend Developer - Java and Spring - 3.5 years]
B --> C[Senior Developer - Ernst and Young - 2 years]
C --> D[DevOps Engineer - CI/CD and Infrastructure]
style A fill:#DBEAFE,stroke:#3B82F6,color:#0F172A
style B fill:#CCFBF1,stroke:#14B8A6,color:#0F172A
style C fill:#E0E7FF,stroke:#6366F1,color:#0F172A
style D fill:#DCFCE7,stroke:#16A34A,color:#0F172A

🎓 Research and Teaching

🔬 MSc Thesis

Blockchain-based Self-Sovereign Identity (SSI)

Decentralized identity management
Verifiable credentials implementation
Privacy-preserving architecture
Enterprise adoption recommendations

👨‍🏫 Teaching Experience

Java: OOP and design patterns
C: systems programming
Python: scripting and algorithms
Linaro Connect: workshop leader
Mentorship: junior developers

🔐 Core Principles

🔒 Security-first -> every system is designed with security at its core
⚙️ Automation-driven -> if it can be automated, it should be
⚡ Performance-focused -> measurable improvements over assumptions
🏗️ Scalable design -> architecture built for growth from day one
📈 Observable systems -> instrumentation is mandatory, not optional
🔄 Continuous improvement -> iterative engineering culture

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