Backend
- C# / .NET (Framework 4.x, .NET 5-10)
- ASP.NET, REST API
- Entity Framework, clean code
Piotr Lebelt
C# .NET developer - from code to infrastructure
I build software that actually helps the team: clean C#, solid APIs, data and CI/CD.
Cover letter
I am a full-stack .NET developer with experience in ERP, banking and internal business apps - mainly backend. I like Agile Scrum, clean code and the moment business requirements turn into a working, maintainable solution. I keep growing on the back end, front end and DevOps - from SQL, PostgreSQL and integrations to Docker and pipelines. I prefer remote work; I'm open to collaboration - get in touch if you're looking for someone for your team or project. Interests: motorcycles, DIY tinkering, embedded systems, Muay Thai. Animals mean a lot to me, especially dogs.
Skills
The stack I use day to day and keep sharpening.
Data
- SQL Server / SSRS / SSIS
- MySQL, Oracle PL/SQL
- Talend ESB, ETL
DevOps & tools
- Docker, Git, Azure DevOps
- OpenSearch, Debezium, logs
- Code review, AI agents
- Postman / Bruno, Agile Scrum
Career path
From IT support and data integration, through ERP, to current .NET work.
-
Developer
Cosinus Łódź, Łódź
hybrid
August 2025 - present
- Develop and maintain internal applications used by the school.
- Build software in C# with .NET; design and ship new IT solutions supporting school operations.
- MS SQL Server 2017+: schema design, query tuning; BI reports for analysis and reporting.
- OpenSearch and Debezium - search plus CDC / change streaming from databases.
- Code review, coding with AI agents; DevOps: logs and system diagnostics.
- Technical analysis of user requirements and troubleshooting production issues.
-
Software Engineer
Knowit, Łódź
hybrid
September 2024 - July 2025
- Work with stakeholders across departments on requirements, application design and progress tracking.
- Analyse and recommend technical solutions aligned with client needs and business goals.
- Build and present prototypes (PoC) to validate new ideas.
- Clean, maintainable code for the client environment; design, coding, code reviews, continuous improvement.
- On-site visits to deepen process knowledge and deliver factory-fit solutions.
-
Growth & projects
independent
July 2023 - August 2024
- Deepening C# / .NET, SQL and clean-code practice outside full-time employment.
- Hands-on with Docker, CI/CD and DevOps tooling; personal projects toward the next role.
-
Associate Engineer
UNIT4, Wrocław
remote
June 2022 - June 2023
- Key ERP modules in C# .NET with focus on purchasing processes.
- Collaborate with senior developers to improve data processing and user workflows.
- Code optimisations and functional improvements from QA and end-user feedback.
- Help configure and maintain Azure DevOps CI/CD pipelines.
- Contribute to RESTful HTTP APIs, external integrations, API security practices and documentation.
- Bug fixing with minimal disruption; QA support in purchasing; code reviews and debugging sessions.
-
ICT Specialist
BFF Banking Group, Łódź
hybrid
January 2019 - February 2022
- C# development: key features, debugging and iterative module delivery to schedule.
- Test and validate changes; detailed reports and feedback to the development team.
- Scalable network services in Talend ESB Studio - data exchange and integration across platforms.
- Design, optimise and maintain SSIS packages; data integrity and ETL automation.
- Monitor package runs and resolve data-processing issues.
-
Process Executive
Infosys, Łódź
on-site
October 2017 - October 2018
- VBA applications and growing C# .NET skills (including web scraping).
- SAP scripts to improve business-process efficiency.
- Primary contact for the client and internally for application maintenance; team mailbox oversight.
- SQL queries supporting data analysis and reporting.
-
Application Programmer - internship
Infosys, Łódź
on-site
July - September 2017
- VBA skills development; apps supporting tools for Infosys clients.
- Kanban for task tracking; business-requirements analysis.
-
Scanning support - internship
Infosys, Łódź
on-site
March - June 2017
- Scan and archive large volumes of documents (invoices) digitally.
- Improve sorting/categorisation; archive documentation; ship archived invoices (Philips client support).
-
IT Freelancer - sole trader
Piotr Lebelt, Łódź
on-site
March - September 2016
- IT systems administration and end-user technical support.
- Configure and prepare workstations; manage hardware and consumables.
- Keep the server room running; Microsoft Active Directory Domain Services (ADDS).
Outside work
What recharges me - plus Python on home projects when C# can take a break.
Motorcycles
A passion that came true after years of putting it off. Shared trips, tinkering and meetups with friends around the machines - service and repairs.
DIY & tinkering
I like fixing things instead of throwing them away. VAG vehicle diagnostics: service, fault analysis and coding new features.
Embedded systems
"How does this work" - DIY projects and my own homelab with the basic tools. Mostly Python and Flask, plus Bootstrap on the front end.
Muay Thai
Physical and mental growth - stress relief, health and fitness.
Animals
I love animals, especially large dogs.
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