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I am a Senior Backend Software Engineer with 10+ years of experience designing and building high-performance, distributed backend systems using Python (Django, Flask) and AWS. I specialize in cloud-native architectures, microservices, and serverless solutions, with a strong focus on reliability, scalability, and maintainability. I enjoy mentoring engineers, advocating clean architecture, and delivering production-grade systems. I routinely implement observability, automate CI/CD pipelines, and collaborate with cross-functional teams to ensure secure, fault-tolerant software in regulated environments.…I am a Senior Backend Software Engineer with 10+ years of experience designing and building high-performance, distributed backend systems using Python (Django, Flask) and AWS. I specialize in cloud-native architectures, microservices, and serverless solutions, with a strong focus on reliability, scalability, and maintainability. I enjoy mentoring engineers, advocating clean architecture, and delivering production-grade systems. I routinely implement observability, automate CI/CD pipelines, and collaborate with cross-functional teams to ensure secure, fault-tolerant software in regulated environments.

Bartosz Wiszewski

Back-End Developer, Programmer, Cloud Developer, +3

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I am a Senior Backend Software Engineer with 10+ years of experience designing and building high-performance, distributed backend systems using Python (Django, Flask) and AWS. I specialize in cloud-native architectures, microservices, and serverless solutions, with a strong focus on reliability, scalability, and maintainability. I enjoy mentoring engineers, advocating clean architecture, and delivering production-grade systems. I routinely implement observability, automate CI/CD pipelines, and collaborate with cross-functional teams to ensure secure, fault-tolerant software in regulated environments.…I am a Senior Backend Software Engineer with 10+ years of experience designing and building high-performance, distributed backend systems using Python (Django, Flask) and AWS. I specialize in cloud-native architectures, microservices, and serverless solutions, with a strong focus on reliability, scalability, and maintainability. I enjoy mentoring engineers, advocating clean architecture, and delivering production-grade systems. I routinely implement observability, automate CI/CD pipelines, and collaborate with cross-functional teams to ensure secure, fault-tolerant software in regulated environments.

Available to hire

I am a Senior Backend Software Engineer with 10+ years of experience designing and building high-performance, distributed backend systems using Python (Django, Flask) and AWS. I specialize in cloud-native architectures, microservices, and serverless solutions, with a strong focus on reliability, scalability, and maintainability.

I enjoy mentoring engineers, advocating clean architecture, and delivering production-grade systems. I routinely implement observability, automate CI/CD pipelines, and collaborate with cross-functional teams to ensure secure, fault-tolerant software in regulated environments.

Skills

Experience Level

Expert

Expert

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Expert

Expert

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Expert

Expert

Expert

Expert

Intermediate

Intermediate

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Intermediate

Intermediate

Intermediate

Work Experience

Programming Trainer at CODING GIANTS

February 1, 2025 - Present

Delivered hands-on training in Python, C#, and software engineering fundamentals, designing real-world coding exercises inspired by enterprise use cases. Mentored students on building projects aligned with modern industry practices, covering object-oriented design, clean code principles, APIs, and database integration. Introduced learners to DevOps concepts (Git, CI/CD pipelines, Docker) and demonstrated cloud workflows using AWS services (Lambda, S3, RDS, EC2). Designed and maintained coding environments, ensuring smooth setup of IDEs, runtime dependencies, and version control systems. Collaborated with other instructors to update the training curriculum, aligning it with professional engineering standards and current tech industry trends.

Programming Trainer at Coding Giants

February 1, 2025 - Present

Delivered hands-on training in Python, C#, and software engineering fundamentals, designing real-world coding exercises inspired by enterprise use cases. Mentored students on building projects aligned with modern industry practices, covering object-oriented design, clean code principles, APIs, and database integration. Introduced learners to DevOps concepts such as Git, CI/CD pipelines, Docker, and demonstrated cloud workflows using AWS services like Lambda, S3, RDS, and EC2. Designed and maintained coding environments, ensuring smooth setup of IDEs, runtime dependencies, and version control. Collaborated with other instructors to update training curriculum, aligning it with professional engineering standards and current tech industry trends.

Junior Software Engineer at SIIPOLAND

September 1, 2023 - October 7, 2025

Contributed to the development of Python and C# backend services, implementing new features and fixing defects under the guidance of senior engineers. Built REST APIs and data processing modules supporting internal financial reporting tools, improving reliability and reducing manual work for analysts. Assisted in migrating legacy codebases from PHP to Python, refactoring modules for maintainability and test coverage. Gained exposure to Docker-based development environments, containerizing services for consistent local testing and deployment. Wrote unit and integration tests (PyTest, NUnit) and collaborated with QA engineers to improve defect detection in pre-production stages. Participated in Agile ceremonies (sprint planning, code reviews, retrospectives), learning industry best practices for collaborative software delivery.

Software Engineer at SIIPOLAND

September 1, 2023 - Present

Architected and delivered core backend services in Python for a real-time trading platform, achieving sub-50ms trade execution latency through optimized memory access patterns and persistent connection pooling. Designed and implemented a high-throughput REST/gRPC API gateway in Python, capable of handling 10,000+ concurrent requests, with built-in rate limiting, retry logic, and deadline propagation to guarantee predictable client performance. Led migration of financial reporting tools from legacy PHP to Python, improving report generation speed by 6x while cutting memory consumption by 70%, enabling faster regulatory compliance reporting. Introduced Kafka-based event streaming and Python workers for trade settlement and event sourcing, ensuring data integrity during peak transaction spikes across millions of records. Enhanced CI/CD pipelines using GitLab CI, Docker, and Kubernetes, reducing build and deployment times by 40%, while embedding PyTest-driven coverage to raise automated te

Junior Software Engineer at Sii Poland

September 1, 2023 - September 3, 2025

Contributed to the development of Python and C# backend services, implementing new features and fixing defects under the guidance of senior engineers. Built REST APIs and data processing modules supporting internal financial reporting tools, improving reliability and reducing manual work for analysts. Assisted in migrating legacy codebases from PHP to Python, refactoring modules for maintainability and test coverage. Gained exposure to Docker-based development environments, containerizing services for consistent local testing and deployment. Wrote unit and integration tests (PyTest, NUnit) and collaborated with QA engineers to improve defect detection in pre-production stages. Participated in Agile ceremonies such as sprint planning, code reviews, and retrospectives, learning industry best practices for collaborative software delivery.

Software Engineer at Sii Poland

September 1, 2023 - Present

Architected and delivered core backend services in Python for a real-time trading platform, achieving sub-50ms trade execution latency through optimized memory access patterns and persistent connection pooling. Designed and implemented a high-throughput REST/gRPC API gateway in Python, capable of handling 10,000+ concurrent requests, with built-in rate limiting, retry logic, and deadline propagation for predictable client performance. Led migration of financial reporting tools from legacy PHP to Python, improving report generation speed by 6x while cutting memory consumption by 70%, enabling faster regulatory compliance reporting. Introduced Kafka-based event streaming and Python workers for trade settlement and event sourcing ensuring data integrity during peak transaction spikes across millions of records. Enhanced CI/CD pipelines using GitLab CI, Docker, and Kubernetes, reducing build and deployment times by 40%, and embedding PyTest-driven coverage to raise automated test adoption.

Web Developer at Cimochowski.com

June 30, 2021 - September 3, 2025

Built a full-stack web application with a Python (Django) backend and React frontend, implementing user authentication, role management, and REST API endpoints. Designed and developed responsive UI components with React, HTML5, CSS3, and Tailwind, ensuring usability across devices. Integrated PostgreSQL as the primary database, optimizing queries and designing relational models for efficient data access. Deployed the application to AWS EC2 using Docker containers, setting up Nginx for reverse proxy and HTTPS configuration. Used Git and GitHub for version control and collaborative code reviews.

Web Developer at CIMOCHOWSKI.COM

June 1, 2021 - October 7, 2025