kokkorogiannis.dev
Konstantinos Kokkorogiannis

Konstantinos Kokkorogiannis

Backend software engineer · Athens, Greece

kostas.kokko97@gmail.comLinkedIn

Open to senior backend roles in Zurich and Geneva.

Profile

Backend software engineer with four years of experience in distributed, mission-critical systems. I build high-throughput backend services for large-scale EU public-sector platforms: systems that must stay correct, resilient, and available while processing large volumes of data. My daily stack is Java, Spring Boot, Kafka, gRPC, and Elasticsearch, deployed on OpenShift / Kubernetes with automated CI/CD. I care about concurrency, correctness under failure, and the engineering practices that keep a codebase honest: SOLID, code reviews, automated testing. Currently focused on AI integration for JVM backends (Spring AI, Model Context Protocol).

Skills

languages
Java (primary), Python, SQL
backend & messaging
Spring Boot, Spring Framework, Quarkus, Apache Kafka, gRPC, REST APIs, Elasticsearch
systems
Concurrent & multi-threaded programming, distributed systems, event-driven architecture
practices
SOLID, API design, microservice patterns, code reviews, Agile / Scrum
cloud & devops
OpenShift, Kubernetes, Docker, CI/CD (Jenkins, Argo CD, GitLab, Maven, Gradle, Ansible)
quality & monitoring
JUnit, Mockito, SonarQube, JMeter, Grafana, Kibana

Experience

Software engineer · ARHS Group (part of Accenture)

Feb 2025 – present

Athens

  • Build low-latency backend services for large-scale EU public-sector interoperability systems, moving data reliably at high volume across a distributed microservices architecture (Java, Spring Boot, Kafka, gRPC); 99% of gRPC requests complete in under 60 ms.
  • Design event-driven data pipelines that keep data correct and consistent across systems, even under failure and heavy load (Kafka, Elasticsearch, idempotent processing).
  • Own features end-to-end, from design through testing to production, in international, cross-functional teams.
  • Contribute to Interface Control Document (ICD) review cycles, helping define and evolve the service interfaces shared across systems and stakeholders.
  • Improve code quality and coverage through automated quality gates (JUnit, Mockito, SonarQube), with CI/CD on Jenkins and Argo CD (GitOps), deployed on OpenShift.
  • Built internal simulator tooling and documentation that teams rely on for integration testing.

Software engineer · Unicorn Domain

Jul 2023 – Feb 2025

Athens

  • Designed, implemented, and tested backend features across microservice-based products (Java, Spring, Quarkus).
  • Verified performance and stability with stress testing and production monitoring (JMeter, Grafana, Kibana).
  • Optimised database access, making key data operations faster and more reliable.
  • Containerised services with Docker and Docker Compose for consistent deployments across environments.

Software engineer · Cognity S.A.

Jun 2022 – Jun 2023

Athens

  • Modernised a legacy Oracle ATG e-commerce monolith by migrating functionality step by step into Spring Boot microservices.
  • Built RESTful web services connecting the legacy platform with the new microservices.
  • Raised unit-test coverage (JUnit, Mockito) and maintained design documentation and test cases.

Software engineer · Center of IT Support of the Hellenic Army (K.E.P.Y.E.S)

Sep 2021 – Jun 2022

Athens

  • Developed and maintained REST APIs and backend services using Java and the Spring Framework.
  • Made data access faster by refactoring SQL queries.
  • Provided training and support to application end users.

Education

MSc, Web Engineering · Harokopio University, Athens

Sep 2020 – Sep 2022

GPA 9.70 / 10. Thesis: a web application for mass vaccination scheduling.

BSc, Computer Science · Harokopio University, Athens

Sep 2016 – Sep 2020

GPA 7.30 / 10. Thesis: a digital repository for physics-education material.

Languages

Greek
native
English
C2
Italian
B2