Available to hire
Hi, I’m Tomasz Kocon, a Senior Backend Engineer with 9 years of experience designing, building, and scaling backend-heavy distributed systems across fintech, enterprise platforms, and cloud-native products. I specialize in Java, Python, Node.js, and .NET with deep expertise in microservices architecture, REST and GraphQL APIs, SQL/NoSQL databases, and cloud platforms including AWS, GCP, and Azure.
I thrive in remote-first, cross-functional teams, delivering high-availability systems, modernizing legacy platforms, and driving backend performance, security, and reliability. I enjoy mentoring teammates, contributing to architecture discussions and documentation, and ensuring alignment across distributed teams.
Skills
Work Experience
Senior Backend Engineer | Cloud & Microservices Specialist at Andersen
June 1, 2024 - PresentLed the design and implementation of cloud-native microservices using Python (Django) and AWS, improving backend scalability and reducing average response times by 35%. Architected event-driven services backed by Amazon DynamoDB with single-digit millisecond latency to support millions of daily requests. Built and maintained containerized services with Docker and Kubernetes, enabling horizontal scaling and improving deployment reliability by 40%. Implemented secure REST APIs with RBAC and token-based authentication, reducing security-related incidents to zero in production. Integrated services across AWS and GCP for hybrid-cloud deployments, automated CI/CD pipelines, and increased uptime to 99.95%. Optimized queries and data models in NoSQL systems, cutting operational costs by approximately 20%. Mentored mid-level engineers and contributed to architecture discussions and documentation in a remote-first environment.
Backend Developer | Java, Python & Node.js Engineer at BlueSoft Sp. o.o.
October 1, 2021 - May 31, 2024Developed and maintained backend services using Java, Python, Node.js, and Go for enterprise-scale applications with thousands of concurrent users. Designed RESTful APIs and asynchronous processing pipelines, increasing throughput by 30% under peak load. Implemented CI/CD workflows with GitHub and Jenkins, reducing manual deployments by over 50%. Refactored legacy components into modular services, improving maintainability and test coverage. Optimized queries and indexes across relational and NoSQL databases to reduce average query time by 40%. Collaborated with frontend and QA teams to deliver end-to-end features with predictable timelines, while applying secure coding practices and conducting regular code reviews.
Backend API Engineer | .NET Developer at One X Tech
April 1, 2019 - June 30, 2021Built and maintained REST APIs using C#, ASP.NET, and the .NET Framework to support internal and customer-facing applications. Designed OO backend components that improved code reuse and reduced defect rates by 25%. Ensured transactional integrity with relational databases, implemented authentication/authorization per security standards, and optimized API performance with caching and efficient data access, reducing response times by up to 30%. Collaborated with frontend teams for API contracts, wrote unit and integration tests, and supported deployments across environments; contributed to migrations toward modern backend patterns and handled production issues.
Java Developer | Spring Backend Engineer at One X Tech
July 1, 2017 - April 30, 2019Developed backend services using Java, Spring Boot, Spring MVC, and Spring Security for enterprise-grade applications. Designed REST APIs to handle complex workflows and external integrations, implemented secure authentication/authorization flows, and collaborated with senior engineers on performance tuning. Worked with Oracle Database and Microsoft SQL Server, optimizing SQL queries and schemas. Improved stability by refactoring legacy code, added robust logging/monitoring, and delivered features on schedule while supporting deployments across multiple environments.
PHP Developer | Web Backend Engineer at HCLTech
March 1, 2015 - May 31, 2017Developed server-side applications using PHP and Laravel for data-driven web platforms. Built RESTful services, designed and maintained MySQL and PostgreSQL schemas, and integrated MongoDB for flexible storage. Optimized backend performance by refactoring queries and application logic, collaborated with frontend teams for full-stack features, and implemented validation, authentication, and authorization mechanisms. Maintained legacy PHP applications while gradually introducing modern Laravel patterns; participated in code reviews and production support.
Education
Bachelor of Computing (Hons) in Mathematical and Computer Science at Nanyang Technological University
January 1, 2010 - December 31, 2014Qualifications
Industry Experience
Software & Internet, Financial Services, Professional Services
Skills
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