Piotr Lebelt

Senior C# .NET - SQL Server, REST API

I build software that actually helps the team: clean C#, solid APIs, data and CI/CD. I also do DevOps and I'm learning frontend.

Get in touch Career path LinkedIn

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.

Backend

C# / .NET (Framework 4.x, .NET 5-10)
Microsoft ASP.NET, REST API
Entity Framework ORM
Clean code
VBA (macros)
Visual Studio

Data

SQL Server 2016+ / SSRS / SSIS
MySQL
Oracle PL/SQL
Talend ESB (ETL / microservices)
OpenSearch, Debezium
Power BI
MS Office (Excel) - advanced

DevOps & tools

Docker
Git
Azure DevOps (CI/CD)
Postman / Bruno / Insomnia
Agile Scrum
Technical documentation
Code review, AI agents

Career path

From IT support and data integration, through ERP, to current .NET work.

Developer 08.2025 - present Cosinus Łódź, Łódźhybrid
- 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; Power 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 consultant 09.2024 - 07.2025 Knowit, client: Dell Technologies, Łódźhybrid
- 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 07.2023 - 08.2024 independent
- 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 06.2022 - 06.2023 UNIT4, Wrocławremote
- 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.
Additional role (August - December 2022): Agile Scrum Master
- Ran Scrum ceremonies: sprint planning, backlog refinement, daily, review and other events.
- Product backlog management and support for the Scrum process during sprints.
- Agile best practices, team cohesion, removing impediments that hurt productivity.
- Partnered with product owners, the team, tech specialists and other Scrum Masters.
ICT Specialist 01.2019 - 02.2022 BFF Banking Group, Łódźhybrid
- 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 10.2017 - 10.2018 Infosys, Łódźon-site
- 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 07.2017 - 09.2017 Infosys, Łódźon-site
- VBA skills development; apps supporting tools for Infosys clients.
- Kanban for task tracking; business-requirements analysis.
Scanning support - internship 03.2017 - 06.2017 Infosys, Łódźon-site
- Scan and archive large volumes of documents (invoices) digitally.
- Improve sorting/categorisation; archive documentation; ship archived invoices (Philips client support).
IT Freelancer - sole trader 03.2016 - 09.2016 Piotr Lebelt, Łódźon-site
- 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

Man does not live by work and IT alone 🙂

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.

Contact

Write about collaboration, a project, or just say hello.