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Laertis Tsekos

@laertistsekos

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Senior backend engineer specializing in Java, Spring, and SQL optimization.

Greece

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What I'm looking for

I seek backend roles where I can improve performance and reliability of transaction-heavy systems, work with Java/Spring microservices, and contribute to observability and automation in collaborative, engineering-driven teams.

I am a Senior Backend Engineer with 10 years designing high-availability, transaction-heavy systems for transportation, fintech, and enterprise clients.

I deliver measurable performance improvements, notably reducing trip-search latency from 75s to 2s and pioneering a dynamic seat-reuse system for real-time bookings.

My core expertise is Java (6/8/11/17), Spring Boot, SQL optimization and microservices, with cross-experience in C#/.NET, Angular and enterprise integration platforms like FileNet.

I focus on reliability, throughput and developer productivity—building reconciliation, payment integration and GDPR-compliant systems while improving operational visibility with reporting and observability tools.

Experience

Work history, roles, and key accomplishments

Current

Senior Java Backend Engineer

Current

AMCO

Jun 2020 - Present (5 years 5 months)

Redesigned database schemas and refactored Java services to reduce trip-search latency from 75s to 2s; delivered high-reliability ticketing modules and a dynamic seat-reuse feature to improve utilization and throughput.

Spring Boot MyBatis MySQL SQL Optimization REST Microservices Grafana Prometheus

C# / .NET WPF Developer

LG CNS

Jun 2019 - Jun 2020 (1 year)

Developed a reliable WPF desktop app for real-time NFC card history and status used by Athens Metro staff and contributed to secure card and ticket issuing system integrations.

C++WPF .NET Framework MSSQL NFC REST Git Desktop Applications

Java / Angular Developer

IKnowHow S.A.

Jun 2018 - Jun 2019 (1 year)

Built a full-stack Spring Boot + Angular enterprise process management platform and extended IBM FileNet P8 with custom Java plugins and integrations.

Spring Boot Angular IBM FileNet P8 Oracle REST Git Enterprise Integration

Full Stack .NET Developer

Ernst & Young

Jun 2017 - Jun 2018 (1 year)

Contributed to C-Star credit-risk reporting and INSEIT cybersecurity platforms, and helped build a GDPR compliance tool for clients, delivering backend components and UI integrations.

C++Dapper MSSQL IIS JavaScript HTML CSS TFS

Java Developer

Ernst & Young

Nov 2015 - Jun 2017 (1 year 7 months)

Implemented INSIS integrations for the insurance sector, developed server-side Java handlers, managed Oracle WebLogic deployments, and authored Groovy SoapUI scripts for batch validation.

Oracle Oracle Weblogic Groovy SoapUI Subversion

Crypto Trading Bot (Personal)

Private Project

Built a Java-based automated trading bot with MySQL backend running on Raspberry Pi that used statistical correlations to rebalance portfolios and produced significant returns over 18+ months.

MySQL REST Linux Automation