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I am a Principal Software Engineer based in Zagreb, Croatia, with extensive experience leading and scaling IoT systems, as well as developing embedded and cloud software solutions. I thrive on solving critical system issues, improving security, and mentoring junior developers. My expertise includes Java and JVM technologies, reverse engineering, AWS cloud setups, Docker optimization, and software migration. I am passionate about technology direction, system observability, and continuous improvement across multinational teams.…I am a Principal Software Engineer based in Zagreb, Croatia, with extensive experience leading and scaling IoT systems, as well as developing embedded and cloud software solutions. I thrive on solving critical system issues, improving security, and mentoring junior developers. My expertise includes Java and JVM technologies, reverse engineering, AWS cloud setups, Docker optimization, and software migration. I am passionate about technology direction, system observability, and continuous improvement across multinational teams.

Hrvoje Spajic

Developer, Programmer, Full Stack Developer, +1

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I am a Principal Software Engineer based in Zagreb, Croatia, with extensive experience leading and scaling IoT systems, as well as developing embedded and cloud software solutions. I thrive on solving critical system issues, improving security, and mentoring junior developers. My expertise includes Java and JVM technologies, reverse engineering, AWS cloud setups, Docker optimization, and software migration. I am passionate about technology direction, system observability, and continuous improvement across multinational teams.…I am a Principal Software Engineer based in Zagreb, Croatia, with extensive experience leading and scaling IoT systems, as well as developing embedded and cloud software solutions. I thrive on solving critical system issues, improving security, and mentoring junior developers. My expertise includes Java and JVM technologies, reverse engineering, AWS cloud setups, Docker optimization, and software migration. I am passionate about technology direction, system observability, and continuous improvement across multinational teams.

Available to hire

I am a Principal Software Engineer based in Zagreb, Croatia, with extensive experience leading and scaling IoT systems, as well as developing embedded and cloud software solutions. I thrive on solving critical system issues, improving security, and mentoring junior developers.

My expertise includes Java and JVM technologies, reverse engineering, AWS cloud setups, Docker optimization, and software migration. I am passionate about technology direction, system observability, and continuous improvement across multinational teams.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Intermediate

Intermediate

Intermediate

Language

Croatian

Fluent

English

Advanced

Spanish; Castilian

Beginner

Work Experience

Principal Software Engineer at Tri plus grupa d.o.o., Zagreb, Croatia – SmartRent subsidiary, NYSE:SMRT

December 1, 2024 - Present

Led upscaling, maintenance, and improvement of core system servers with more than 700,000 connected IoT gateways serving millions of devices. Defined Java/JVM development guidelines for multinational teams and contributed to technological direction. Detected and resolved critical system issues through metrics and memory analysis. Mitigated malware infections on company servers, preventing potential breaches, and revisited security audits to identify vulnerabilities and ensure best practice adherence.

Software Engineer at Tri plus grupa d.o.o., Zagreb, Croatia – SmartRent subsidiary, NYSE:SMRT

December 1, 2024 - August 22, 2025

Led the design and development of a Video Management System to replace proprietary third-party solutions deployed on thousands of devices, involving reverse engineering. Developed and optimized software for embedded devices and cloud servers using Java on custom Linux and Android systems and Spring/Spring Boot frameworks. Led migration of cloud software to new Java and Spring Boot versions. Mentored junior developers.

Junior Software Engineer at Tri plus grupa d.o.o., Zagreb, Croatia – SmartRent subsidiary, NYSE:SMRT

January 1, 2022 - August 22, 2025

Implemented new features and architectural optimizations. Improved service stability significantly by reducing failures. Addressed security vulnerabilities to enhance system safety.

Junior Software Engineer (Student contract – Full Time) at CROZ d.o.o., Zagreb, Croatia

November 1, 2020 - August 22, 2025

Developed telecom services using Spring, MongoDB, Keycloak, and CentOS.

Intern Software Engineer (Student contract – Full Time) at Amphinicy d.o.o., Zagreb, Croatia

November 1, 2019 - August 22, 2025

Developed a router simulator which communicates with satellites and mobile applications.

Junior Software Engineer (Student contract – Full Time) at CROZ d.o.o., Zagreb, Croatia

May 1, 2019 - August 22, 2025

Created a document generator application used by government services and banks.