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I am a Senior Software Engineer with over 9 years of experience building React, Next.js, Node.js, TypeScript, Python, and AI-agent–driven full-stack systems for large-scale, consumer-facing platforms. I specialize in high-performance React applications, cloud-native backend services, and LLM-based AI systems, with deep expertise in scalable architecture, microservices, and secure engineering practices. My career demonstrates clear progression from internship-level engineering foundations to senior technical leadership, driving architectural decisions, system scalability, and measurable business impact in fintech, platform engineering, and cloud-first products.…I am a Senior Software Engineer with over 9 years of experience building React, Next.js, Node.js, TypeScript, Python, and AI-agent–driven full-stack systems for large-scale, consumer-facing platforms. I specialize in high-performance React applications, cloud-native backend services, and LLM-based AI systems, with deep expertise in scalable architecture, microservices, and secure engineering practices. My career demonstrates clear progression from internship-level engineering foundations to senior technical leadership, driving architectural decisions, system scalability, and measurable business impact in fintech, platform engineering, and cloud-first products.

PIOTR LENARCIAK

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I am a Senior Software Engineer with over 9 years of experience building React, Next.js, Node.js, TypeScript, Python, and AI-agent–driven full-stack systems for large-scale, consumer-facing platforms. I specialize in high-performance React applications, cloud-native backend services, and LLM-based AI systems, with deep expertise in scalable architecture, microservices, and secure engineering practices. My career demonstrates clear progression from internship-level engineering foundations to senior technical leadership, driving architectural decisions, system scalability, and measurable business impact in fintech, platform engineering, and cloud-first products.…I am a Senior Software Engineer with over 9 years of experience building React, Next.js, Node.js, TypeScript, Python, and AI-agent–driven full-stack systems for large-scale, consumer-facing platforms. I specialize in high-performance React applications, cloud-native backend services, and LLM-based AI systems, with deep expertise in scalable architecture, microservices, and secure engineering practices. My career demonstrates clear progression from internship-level engineering foundations to senior technical leadership, driving architectural decisions, system scalability, and measurable business impact in fintech, platform engineering, and cloud-first products.

Available to hire

I am a Senior Software Engineer with over 9 years of experience building React, Next.js, Node.js, TypeScript, Python, and AI-agent–driven full-stack systems for large-scale, consumer-facing platforms.

I specialize in high-performance React applications, cloud-native backend services, and LLM-based AI systems, with deep expertise in scalable architecture, microservices, and secure engineering practices. My career demonstrates clear progression from internship-level engineering foundations to senior technical leadership, driving architectural decisions, system scalability, and measurable business impact in fintech, platform engineering, and cloud-first products.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Language

English

Fluent

Work Experience

Senior Software Engineer at Netlight

September 1, 2023 - Present

Led development of large-scale React and Next.js applications with TypeScript, improving page load performance by 35% through optimized rendering and code-splitting. Architected Redux-based state management for complex user flows, reducing production defects by 30%. Integrated React frontends with Node.js microservices, ensuring reliable API communication and reducing data inconsistencies by 25%. Implemented CI/CD pipelines with Jest-based automated testing, doubling deployment frequency while maintaining stability. Contributed to cloud-first architectural decisions on AWS, enabling horizontal scaling for high-traffic applications. Delivered WCAG-compliant, responsive UI components increasing user engagement by 20%.

Senior Full Stack Engineer at Automattic

July 1, 2021 - August 1, 2023

Built and scaled consumer-facing React and Next.js applications supporting millions of active users with consistent performance. Developed Node.js backend services and APIs, improving request throughput by 40% through query and caching optimization. Designed reusable React component systems, reducing feature delivery time by 25%. Integrated frontend applications with cloud-native services on AWS, improving global reliability and latency. Led code reviews and enforced testing standards using Jest, reducing post-release defects by 30%.

Back End Developer at Canonical

January 1, 2020 - June 1, 2021

Developed backend services using Node.js and Python for enterprise-grade distributed platforms. Improved existing core services and APIs, reducing response times by 20%. Authored complex PostgreSQL queries for compliance and reporting, ensuring data accuracy and reliability. Collaborated with frontend teams building React applications, ensuring smooth API integration. Expanded expertise in microservices and distributed system design, preparing for senior-level responsibilities.

Backend Developer at Aiven

January 1, 2017 - December 1, 2019

Implemented backend services using Node.js and Python, supporting cloud-managed infrastructure platforms. Optimized PostgreSQL and MySQL performance, reducing operational incidents by 15%. Contributed to microservices-based architectures, improving scalability and fault isolation. Added automated tests and monitoring, increasing system reliability and observability. Progressed from task-based execution to independent ownership of backend components, delivering production-grade services.

Finance Intern at GovTech Singapore

April 1, 2016 - December 1, 2016

Built Python-based data analysis scripts, improving financial reporting accuracy and reducing manual effort by 20%. Wrote SQL queries to analyze transactional datasets, supporting compliance and audit requirements. Assisted in automating internal financial workflows, increasing processing efficiency and reliability. Collaborated with engineers and analysts, gaining early exposure to structured software development practices. Established foundational problem-solving and analytical skills for a full-time engineering career.