11/04/2026 updated
100 % available
Senior .NET Backend Developer | C# | Web API | CI/CD | Microservices
Ostrow Wielkopolski, Poland
Only remote
MSc in Computer Science, Wroclaw University of Science and TechnologyAbout me
Senior .NET Developer with 15+ years of experience and a strong ownership mindset, including 8+ years building distributed systems for global investment banks (HSBC, Credit Suisse). Proactive and self-sufficient, working fully remotely in international team
GitHub CopilotMicrosoft SQL ServersAnsibleOracle 10g/11gTeamcity
.NET / C# Backend Development
15+ years of designing and building backend systems with .NET, .NET Core, C#, Web API and REST, including 8+ years for global investment banks (HSBC, Credit Suisse). Designed and developed a distributed data platform used by 1,500+ users across HSBC.
Data Engineering, ETL & SQL
Deep expertise in SQL Server, Oracle and MySQL. Built and maintained ETL jobs on Windows servers and Kubernetes: 3,000+ job executions and 700M+ rows loaded per day.
Microservices & Event-Driven Architecture
Built and maintained 20+ REST APIs and event-driven integrations based on Solace messaging in large-scale banking environments.
AI-Assisted Development
Daily practitioner of AI-assisted development: GitHub Copilot in commercial work, Claude Code and OpenAI Codex in personal projects. Focus on test generation and code review support, with critical review of AI-generated code to keep quality high.
Legacy Modernization
Migrated and refactored ETL jobs from .NET Framework to .NET Core. Extracted an attachments service from a monolith application. Migrated MSSQL and Sybase monitoring from a legacy tool to a new platform.
CI/CD & DevOps
Owned CI/CD and deployment automation with TeamCity, Ansible and PowerShell. Windows and IIS administration. Working knowledge of Docker, Kubernetes and GCP.
Full-Stack with Angular & TypeScript
Web applications combining .NET backends with Angular and TypeScript frontends, including monitoring solutions at Credit Suisse. Earlier experience with PHP, JavaScript and MySQL (web and e-commerce).
Experience
Professional experience10+ years
Freelancer since2021
Languages
EnglishGoodPolishNative speaker
Project history
Designing and developing a distributed data platform used by 1,500+ users across the bank using C#, .NET Core, Web API, Angular and MS SQL. Building and maintaining 20+ REST APIs and event-driven integrations based on Solace messaging. Developing ETL jobs running on Windows servers and Kubernetes processing 3,000+ job executions daily and loading 700M+ rows of data per day. Owning CI/CD and deployment automation with TeamCity and Ansible. AI-assisted development using GitHub Copilot for test generation and code review. Achievements include migrating ETL jobs from .NET Framework to .NET Core, implementing new features such as security token for file download, and extracting attachments service from monolith application.
Designing and developing monitoring solutions using .NET, C# and Angular. Developing web applications with Angular, .Net, Webservice, Rest API and Oracle. Gathering requirements for owned components and designing new features. Creating technical documentation. Achievements include migrating MSSQL and Sybase monitoring from legacy tools to new projects.
Designing and development of web applications using .NET, C#, PHP, JavaScript, MSSQL, MySQL, jQuery, AJAX, Web Service and Rest API. Finalizing IT projects including a Project Management System for a Design Company and a Voting web application for Citizen Budget.