Piotr N.
Senior Software Engineer
Experience
Sep 2021 - Present
4 years 3 monthsLondon, United Kingdom
Senior Software Engineer
Pagepro
- Developed and optimized scalable backends using Java, Spring Boot, Spring Data JPA, and Hibernate, increasing system scalability and reducing latency by 28%.
- Designed RESTful APIs with Spring MVC, Spring Web, and Jackson, enabling seamless integration with React frontends and third-party services.
- Engineered and maintained microservices infrastructure using Golang, Java, and Node.js, enabling fault-tolerant, high-performance backend systems that supported large-scale, distributed applications.
- Designed and optimized data storage and caching layers using SQL, PostgreSQL, H2, NoSQL, MongoDB, and Redis, improving query efficiency and ensuring data integrity across high-traffic, distributed backend systems.
- Integrated authentication and authorization with Spring Security and JWT, enforcing role-based access control and enhancing application security.
- Implemented event-driven architecture using Spring Kafka and Apache Kafka clients, improving real-time data processing by 40%.
- Optimized backend performance by leveraging Micrometer and Spring Boot Actuator, monitoring metrics, and improving response times by 15%.
- Designed and developed dynamic, high-performance web interfaces using React, Next.js, and TypeScript, while building scalable and reusable UI component libraries with Redux, Context API, React Hook Form, React Query, Tailwind CSS, and Styled-Components, enhancing user engagement and maintaining consistent UX across multiple cross-functional projects.
- Improved React application performance by 20% by migrating to Vite, applying lazy loading and code splitting, and implementing scalable state management with Redux, MobX, and Context API.
- Integrated machine learning models into Spring Boot backend APIs, enabling predictive analytics and data-driven features for frontend React applications.
- Exposed ML model predictions via REST APIs for seamless consumption by frontend React/Next.js components, improving app interactivity.
- Automated CI/CD pipelines using Jenkins, Docker, and Kubernetes on cloud platforms including AWS and Azure, streamlining deployments and reducing errors in production releases.
- Mentored junior and mid-level developers through code reviews, pair programming, and technical workshops, with a focus on cloud-native design patterns, Kubernetes best practices, and Golang development.
Jun 2019 - Aug 2021
2 years 3 monthsWarsaw, Poland
Full Stack Engineer
Omnipack
- Developed a microservices-based Order Management System using Java, Spring Boot, and RESTful APIs, improving order processing efficiency through modular architecture and asynchronous communication.
- Engineered a real-time inventory dashboard with React, Redux, Material UI, and Axios, collaborating with designers via Figma and seamlessly integrating backend APIs to provide live stock visibility and reduce inventory discrepancies by 22%.
- Implemented event-driven architecture using Kafka for order status updates, enhancing system scalability, ensuring message reliability, and reducing notification latency across distributed services.
- Optimized complex SQL queries and redesigned database schemas in PostgreSQL for the warehouse management system, reducing average data retrieval time by 32% and improving transaction throughput.
- Integrated GraphQL and third-party APIs, enabling efficient, client-specific data fetching and automating return workflows, cutting manual processing time by 36% and eliminating over-fetching issues.
- Built a real-time shipment tracking system using WebSockets, delivering live delivery updates to users and improving customer satisfaction through enhanced transparency.
- Established robust test automation with JUnit and Mockito, and implemented CI/CD pipelines using Jenkins, Docker, and GitHub Actions, achieving 87% test coverage and reducing release cycle time.
Oct 2015 - Jul 2019
3 years 10 monthsWarsaw, Poland
Full Stack Developer
Zabka Polska
- Developed and optimized Java-based microservices to handle high-traffic e-commerce transactions, leveraging Spring Boot, Apache Kafka, and SQL databases, resulting in a 25% reduction in response time and improved system scalability.
- Engineered RESTful APIs for seamless integration between frontend applications and backend services, utilizing Java, Spring Boot, and JPA/Hibernate, enhancing data consistency and reducing latency by 25%.
- Implemented event-driven architecture using Apache Kafka, enabling real-time data processing and synchronization across multiple services, leading to a 40% increase in system responsiveness.
- Designed and developed dynamic, responsive user interfaces using React, Redux, and TypeScript, improving user engagement and reducing bounce rates by 20%.
- Collaborated with UX/UI designers to translate wireframes and mockups into high-quality code, ensuring cross-browser compatibility and adherence to accessibility standards.
- Optimized SQL queries and database schemas, resulting in a 15% improvement in data retrieval times and enhanced overall application performance.
- Implemented Continuous Integration and Continuous Deployment (CI/CD) pipelines using Jenkins and Docker, streamlining the deployment process and reducing deployment times by 50%.
- Collaborated with cross-functional teams, including QA, DevOps, and product managers, to deliver high-quality software solutions on time and within scope.
Summary
Senior Full Stack Engineer with over 9 years of experience building scalable, high-performance web applications and distributed backend systems. Recognized as a subject matter expert in Java, Golang, Node.js, React and Angular, with a strong track record of leading end-to-end feature development in Agile, cross-functional teams. Skilled at translating business requirements into clean, maintainable code, and collaborating closely with product, design, and QA to deliver impactful solutions. Known for mentoring junior developers, driving technical best practices, and maintaining high standards of code quality. Detail-oriented, adaptable, and passionate about continuous improvement and delivering reliable, user-centric software.
Languages
Polish
NativeEnglish
AdvancedEducation
Oct 2012 - Sep 2015
Vistula Academy of Finance and Business
Bachelor · Computer Science · Warsaw, Poland · 4.5
Certifications & licenses
Aws Certified Developer – Associate (Java-focused projects)
Amazon Web Services
Oracle Certified Professional: Java Se 21 Developer
Oracle
Spring Professional Certification
VMware
Need a freelancer? Find your match in seconds.
Try FRATCH GPT More actions
Similar Freelancers
Discover other experts with similar qualifications and experience
- English
- Deutsch
2025 © FRATCH.IO GmbH. All rights reserved.