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Greece

Senior Software Engineer & Team Lead

Marios Mantratzis

Building backend-heavy, cloud-native software systems. Specializing in distributed architectures, secure API platforms, and high-availability microservices at scale.

JavaSpring BootAzureKubernetesDistributed SystemsMicroservicesEvent-Driven Architecture
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About.

Senior Software Engineer and Team Lead with 16+ years of engineering experience and 8+ years of professional work experience building backend-heavy, cloud-native software systems across enterprise and multi-service environments.

Core expertise in Java, Spring Boot, distributed systems, event-driven architectures, secure API platforms, and microservices, with strong hands-on experience in Azure, Kubernetes, Docker, and full-stack delivery with Angular and React when end-to-end ownership is needed.

Proven track record in leading engineering efforts across backend, cloud, and full-stack initiatives—contributing to system design, API security, DevOps practices, performance optimization, mentoring, and code reviews. Delivered and supported large-scale systems involving 10+ production projects.

Core Expertise.

Technology experience matrix spanning backend, cloud infrastructure, distributed systems, and full-stack delivery.

Backend Engineering

Java16 yr total8 yr workSpring Boot9 yr total8 yr workREST APIs11 yr total8 yr workNode.js3 yrSOAP2 yr total1 yr workPHP3 yr total6 mo workPython3 yr total2 mo work

Distributed Systems

Microservices8 yrEvent-Driven Architecture6 yrKafka2 yrRabbitMQ2 yrAzure Service Bus2 yrAzure Event Hub2 yr

Cloud & Infrastructure

Microsoft Azure2 yrAWS2 yrKubernetes3 yrDocker7 yr

Databases

PostgreSQL4 yrAzure Cosmos DB2 yrOracle3 yrMongoDB2 yrRedis3 yrAurora MySQL2 yrMariaDB2 yrMySQL2 yrDynamoDB1 yr

Testing

JUnit8 yrJMeter4 yrSelenium2 yrBDD1 yrCucumber1 yrGherkin1 yr

DevOps

Jenkins5 yrBicep IaC2 yrAWS SAM IaC2 yrELK stack2 yrAzure DevOps pipelines2 yrArgoCD1 yrAWS CDK IaC1 yrNexus OSS1 yrGrafana/Loki6 mo

Security & Identity

OAuth24 yrOpenID Connect3 yrJWT2 yrMicrosoft Entra ID2 yrKeycloak2 yrmTLS (Istio, Linkerd)2 yrAWS Cognito2 yrSAML2 yr

Frontend & Mobile

JavaScript / TypeScript16 yr total8 yr workAngular7 yr total6 yr workReact3 yrAndroid SDK3 yrKotlin1 yr
Expert
Advanced
Intermediate
Beginner

total = all experience · work = professional

Selected Impact.

16+
Years of Engineering
Building software systems since 2010
8+
Years of Engineering Work Experience
Professional enterprise-scale software engineering
10+
Production Projects
On-premises, cloud, and hybrid multi-service systems
Applied reliability patterns including idempotency keys, retry mechanisms, and asynchronous workflows.
Led and scaled engineering teams, delegated technical work, tracked delivery timelines, actively unblocked engineers through daily collaboration, and mentored engineers through code reviews and cross-team technical coordination.
Led backend and cloud engineering across large-scale systems involving many microservices.
Designed and delivered Azure-based cloud-native systems using App Services, Functions, Cosmos DB, Event Hubs, Service Bus, APIM, and Bicep, and contributed to AWS-based systems using Lambda, Cognito, Aurora MySQL, AWS SAM, and Cognito integration in Angular applications via AWS Amplify.
Designed and implemented event-driven architectures using Kafka, RabbitMQ, Azure Service Bus, and Azure Event Hub.
Replaced Ehcache with Redis-based distributed caching to improve scalability and consistency, and designed resilient deployment and caching strategies across Kubernetes and Redis-based environments.
Authored Kubernetes manifests and Helm charts, led the migration of on-premise Spring Boot microservices into Dockerized Kubernetes environments, implemented service mesh capabilities for mTLS and observability across distributed services, and improved Kubernetes resilience through node-aware pod distribution strategies.
Designed modular architecture using micro-frontends (MFEs), SPI, and shared modules across backend and frontend systems, and introduced shared parent/common modules, SPI modules, and reusable UI libraries across teams and microservices.
Implemented dynamic runtime extensibility using polymorphism, service loaders, dependency injection, and dynamic routing, and enabled dynamic feature composition through runtime route and component injection based on data-driven configuration.
Contributed to architectural decision-making and Software Architecture Document (SAD) definition.
Contributed to security and compliance-related engineering including encryption, access control, logging, auditability, and key management, and supported security and privacy assessments aligned with enterprise and regulatory control frameworks across infrastructure and application layers.
Designed secure browser-isolation mechanisms for safe rendering of dynamic HTML and document content using controlled cross-origin communication patterns.
Applied BDD testing practices using Cucumber and Gherkin, implemented Selenium-based end-to-end testing, built and maintained CI/CD pipelines using Jenkins, Azure DevOps, ArgoCD, Nexus OSS, and Azure Artifacts, and integrated SonarQube to improve code quality, maintainability, and release reliability.
Advocated Infrastructure-as-Code best practices by promoting Bicep-based provisioning over imperative scripting for multi-environment systems.
Achieved significant performance gains by eliminating query-in-loop patterns, introducing bulk data fetching, optimizing algorithms using O(1) lookup structures, improving concurrency stability through thread-safe random generation, and enhancing database throughput through JPA batch processing configuration.
Supported cross-team engineering for performance, scalability, and reliability.
Contributed to the migration of legacy monolithic systems to Spring Boot microservices, led frontend modernization from AngularJS to Angular, introduced centralized logging and monitoring using the ELK stack, and delivered backend and frontend improvements across enterprise software projects.
Developed backend and frontend features across enterprise software projects, improved Angular performance by avoiding DOM re-rendering bottlenecks through property-based conditional directives instead of function-based approaches, and supported production deployments and CI/CD processes.

Experience.

Senior Software Engineer & Team Lead

European Dynamics

Nov 2019 — Present

Senior Software Engineer

European Dynamics

Feb 2019 — Nov 2019

Software Engineer

European Dynamics

Aug 2018 — Jan 2019

Software Developer

European Dynamics

Jan 2018 — Jul 2018

Military Service — Special Forces

Hellenic Army · Amphibious Commando

Completed
  • Completed mandatory military service in the Hellenic Army Special Forces in an amphibious commando role.
  • Developed discipline, resilience, teamwork, and the ability to perform effectively under pressure.

Certifications.

Professional Certifications

Azure Data Fundamentals

Microsoft

Validity: 2026 - No expiration

Azure Administrator Associate

Microsoft

Validity: 2025 - Present

Azure Developer Associate

Microsoft

Validity: 2025 - Present

Azure Fundamentals

Microsoft

Validity: 2024 - No expiration

Certificates of Completion

SOLID Principles: Introducing Software Architecture & Design

Udemy · 2023 - 2023

Validity: No expiration

Cloud Developer Nanodegree

Udacity · 2023 - 2023

Validity: No expiration

Learn Apache Camel Framework with Spring Boot

Udemy · 2023 - 2023

Validity: No expiration

Education

National and Kapodistrian University of Athens

Bachelor's Degree, Department of Informations and Telecommunications · 2016

Bachelor Thesis

Software System for Collecting Cellular and Wi-Fi Network Information Using an Android Device

View Thesis

Languages

Greek

Greece

Native

Native language

English

United States

Professional Working Proficiency

Michigan HAU B2 (2007) · Duolingo score: 130

Japanese

Japan

Elementary Proficiency

Duolingo score: 12

Current Interests.

Beyond day-to-day engineering, areas of active exploration and development.

Applied AI & Computer Vision

Experimentation in image recognition, object detection, and image segmentation using Python and TensorFlow.

Android Product Development

Building mobile applications with a focus on real-world utility and modern Android development practices.

Data Platform Exploration

Exploring lakehouse architectures, media-data platforms, and modern data engineering workflows.

Get in Touch.

Connect on LinkedInView GitHub