Peter K. - Senior Software Engineer

Kielce, Poland

Experience

Oct 2022 - Oct 2025

3 years 1 month

Romania

Senior Software Engineer

LiftUP

Led AI/LLM training project leveraging Ruby and Python, integrating multi-language datasets, optimizing model performance, and annotating complex data samples.
Designed and implemented containerized LLM training environments using Docker and Kubernetes, ensuring reproducible deployments and scalable infrastructure across cloud providers.
Performed extensive code review and debugging in Ruby and Python, identifying code smells, anti-patterns, and optimizing application performance in AI pipelines.
Implemented CI/CD pipelines using GitHub Actions and Jenkins, automating testing, deployment, and monitoring of LLM projects for consistent delivery.
Collaborated with data engineers and solution architects to benchmark AI models, analyze outputs, and refine training datasets to improve accuracy by over 20%.
Developed internal Ruby scripts for automation of repetitive tasks, including data cleaning, preprocessing, and sandboxed agent-based code execution for LLM evaluation.
Documented high-quality technical notes, test results, and defect tracking to ensure maintainability and reproducibility across multiple AI projects.
Mentored junior engineers in Ruby, Python, and containerized development practices, fostering knowledge sharing on AI model training and deployment.
Integrated monitoring tools such as Prometheus and Grafana to track model performance, system metrics, and infrastructure health across environments.
Optimized multi-language LLM training workflows, reducing resource usage and training time while maintaining model accuracy and stability.
Developed APIs and data pipelines to feed training data efficiently into LLMs, ensuring compliance with data security and governance policies.
Collaborated with project leads to adapt guidelines for new AI domains, ensuring flexible adoption and continuous improvement in model quality.

Mar 2020 - Sep 2022

2 years 7 months

Faro, Portugal

Senior Full Stack Engineer

SOFTLOFT

Developed and maintained web applications using Ruby on Rails and React, integrating AI-assisted code review tools to improve developer productivity.
Implemented containerized development and deployment workflows using Docker and Kubernetes, reducing release cycle times by 30%.
Built and integrated REST and GraphQL APIs to enable real-time data flow between AI tools and frontend applications.
Collaborated with cross-functional teams to optimize ML-powered features and enhance system performance and scalability in client-facing applications.
Led technical design and code review sessions to ensure adherence to best practices, OOP principles, and Ruby idioms across projects.
Developed automation scripts in Ruby for data processing and testing, improving code quality and reducing manual intervention.
Integrated monitoring and logging solutions, including Grafana and ElasticSearch, to ensure system reliability and quick incident resolution.
Documented development processes, test coverage, and AI integration approaches for future onboarding and maintenance purposes.
Participated in LLM pilot projects by validating prompt generation, evaluating outputs, and providing actionable feedback to improve model performance.
Mentored junior engineers in full-stack development and best practices for code quality, testing, and deployment automation.
Engaged with project leads to assess AI integration opportunities, delivering insights to enhance product features and user experience.

Apr 2019 - Mar 2020

1 year

Cupertino, United States

Full Stack Developer

Sibedge

Implemented web applications using Ruby on Rails and React, supporting automated data processing and testing pipelines for AI/ML experiments.
Developed CI/CD workflows using GitLab CI and Docker, streamlining deployment of multi-language applications and improving system reliability.
Performed Ruby code reviews, refactored legacy code, and addressed test gaps to maintain high-quality standards in production environments.
Built APIs and integrated third-party services to enhance application functionality, focusing on AI-driven data workflows and user interactions.
Created and maintained technical documentation, defect tracking, and test reports to support knowledge sharing and reproducibility.
Supported pilot AI projects by evaluating generated outputs, documenting anomalies, and refining workflows to improve LLM performance.
Optimized database queries and data pipelines for high-performance data handling, ensuring accurate and efficient AI model training.
Collaborated with DevOps teams to deploy containerized solutions and manage environment configurations for AI experiments.
Mentored team members on best practices in Ruby, automated testing, and CI/CD, fostering technical growth and productivity.

May 2016 - Mar 2019

2 years 11 months

Poznań, Poland

Junior Full Stack Developer

Netguru

Assisted in building full-stack applications using Ruby on Rails, React, and PostgreSQL, contributing to data processing and AI model integration tasks.
Participated in code reviews, learning Ruby best practices, OOP principles, and testing methodologies to improve code quality and maintainability.
Supported CI/CD pipeline setup with GitHub Actions, ensuring smooth deployment of web applications and automated test execution.
Developed helper scripts and small modules in Ruby and Python to preprocess data for internal AI and analytics projects.
Documented development tasks, test cases, and bug reports to improve project transparency and team collaboration.
Worked with containerized environments using Docker to develop, test, and deploy applications consistently across platforms.
Assisted in integrating APIs and external services, gaining experience in automation and AI-powered tool adoption within projects.
Collaborated with senior developers to troubleshoot issues, debug applications, and learn best practices in full-stack software engineering.