Senior Software Engineer with 12+ years of experience designing and implementing robust, scalable backend systems, architecting APIs, and improving system efficiency and security. Experienced in troubleshooting complex issues, collaborating across diverse tech stacks, and maintaining high engineering standards. I’m passionate about clean code, best practices, and continuous learning. I also enjoy mentoring and sharing knowledge, and I’m always open to new technical challenges and innovative projects.

Arnas Grigaliūnas

Senior Software Engineer with 12+ years of experience designing and implementing robust, scalable backend systems, architecting APIs, and improving system efficiency and security. Experienced in troubleshooting complex issues, collaborating across diverse tech stacks, and maintaining high engineering standards. I’m passionate about clean code, best practices, and continuous learning. I also enjoy mentoring and sharing knowledge, and I’m always open to new technical challenges and innovative projects.

Available to hire

Senior Software Engineer with 12+ years of experience designing and implementing robust, scalable backend systems, architecting APIs, and improving system efficiency and security. Experienced in troubleshooting complex issues, collaborating across diverse tech stacks, and maintaining high engineering standards.

I’m passionate about clean code, best practices, and continuous learning. I also enjoy mentoring and sharing knowledge, and I’m always open to new technical challenges and innovative projects.

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Experience Level

Expert
Expert
Expert
Expert
Expert
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
See more

Language

English
Fluent
Lithuanian
Fluent
Russian
Beginner

Work Experience

Senior Back-End Developer at OBDeleven
January 1, 2026 - Present
Senior Back-End Engineer at Kilo Health
December 1, 2024 - January 1, 2026
Developing and maintaining scalable health technology solutions using a diverse tech stack. Applying best practices in software engineering within a fast-paced healthcare technology environment.
Python Lecturer at Vilnius CODING School
March 1, 2024 - August 1, 2024
Software Engineer at Notified Software
March 1, 2023 - December 1, 2024
Developed and maintained features for the Earnings Calls and Webcasts platform, improving user experience and operational efficiency. Designed and developed APIs to integrate services securely. Troubleshot production issues and identified root causes. Collaborated with a multi-language tech stack including Python, PHP, TypeScript, and JavaScript. Addressed security vulnerabilities and served as point of contact for security topics (Dependabot priority issues, Veracode scans and flaw remediation/mitigation). Acted as point of contact for a key new API project integrated into the Webcasts platform, guiding API development best practices (coding standards, validation, authentication, documentation, unit testing using Python Bottle). Ensured local development environment configuration.
Software Developer at Smartproxy
December 1, 2022 - March 1, 2023
Software Engineer at Oxylabs.io
March 1, 2022 - December 1, 2022
Worked on e-commerce websites and built backend services/microservices. Implemented a Dynamic Pricing feature based on traffic data and IP parameters. Designed APIs with caching using Redis and database integration. Integrated external payment processing and created webhook endpoint to process upcoming payments. Implemented message queue listeners to assign proxies after payment events, storing proxies securely for UI display. Participated in a mentorship program (OOP, databases, APIs, testing, deployment, caching; Python, FastAPI, GCP).
Mentor at bit&Byte
November 1, 2021 - May 1, 2022
Mentored 7–14-year-old kids in creative technology at the Creative Technology Academy. Contributed to weekly classes and initiatives aimed at developing courageous, curious, team-working creative technologists.
Software Engineer at Oxylabs.io
March 1, 2021 - March 1, 2022
Worked with a web scraping tool; responsibilities included building and maintaining APIs and high-performance microservices, plus troubleshooting and root-cause analysis.
Software Engineer at Estina
July 1, 2020 - March 1, 2021
Created and fixed major e-commerce store functionality. Designed and implemented APIs, optimized API performance, and built integration with an external system to automatically translate product descriptions into different languages.
PHP Developer at Genius Sports Group
November 1, 2019 - July 1, 2020
Developed a competition management system. Designed and implemented RESTful APIs, integrated with an existing data collection system, and built core functionality used to manage competitions.
Python Developer at Genius Sports Group
July 1, 2018 - July 1, 2020
Developed a football competition management system. Designed and implemented RESTful APIs, investigated issues and resolved defects, created integrations with existing systems, and built major functionality used across the overall system.
Python Developer at Visma Lietuva
February 1, 2017 - July 1, 2018
Created new integrations and migrated existing integrations.
Intern (NFQ Academy) at NFQ Academy
October 1, 2016 - December 1, 2016
Internship included practice, lectures, workshops, and development of a web project within a team.
Assistant in Oracle programming group at Lietuvos draudimas, AB
September 1, 2016 - September 1, 2016
Managed incidents (forms, reports) and worked with Oracle database.

Education

Bachelor's degree (Computer Science) at Vilniaus Universitetas
January 1, 2013 - January 1, 2017

Qualifications

Google Cloud Platform Fundamentals: Core Infrastructure (certification)
January 11, 2030 - July 23, 2026
AWS Certified Developer – Associate (certification)
January 11, 2030 - July 23, 2026
Introduction to Generative AI (certification)
January 11, 2030 - July 23, 2026
NFQ Technologies - PHP Academy Certificate
January 11, 2030 - July 23, 2026

Industry Experience

Software & Internet, Healthcare, Education, Financial Services, Professional Services

Experience Level

Expert
Expert
Expert
Expert
Expert
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
See more