Rafał Łańcucki, Developer in Nieborowice, Poland
Rafał is available for hire
Hire Rafał

Rafał Łańcucki

Verified Expert  in Engineering

Software Developer

Nieborowice, Poland
Toptal Member Since
January 29, 2018

Rafał has over 18 years of experience in software development, maintenance, and troubleshooting. In his career, he has developed every possible kind of software (with the exception of low-level hardware drivers). Rafał enjoys implementing front ends, back ends, and databases in every technology or programming language. He is a calm and skillful team player who always finds the solutions to even complex problems.


Freelancing, Amazon Web Services (AWS), AWS Data Pipeline Service, AWS Lambda...
Freelancing, NgRx/store, .NET Core, Angular, Node.js, ASP.NET Core, TypeScript...
Freelancing, Angular, Leaflet, GeoServer, ArcGIS Server, GIS, TypeScript, CSS...




Preferred Environment

Freelancing, Git, Visual Studio Code (VS Code), Visual Studio, Windows

The most amazing...

...thing I've coded is software that delivers automatic updates to more than 3,000 workstations worldwide; it continued to work for years without breaking down.

Work Experience

Senior Full-stack Developer

2020 - 2020
  • Created an administration module in a serverless application allowing more customized events.
  • Worked on an AWS RDS database that was used to store statistical data about all users participating in the event and their time spent on particular pages.
  • Worked on a security system using AWS Lambda and an AWS RDS database in concatenation with AWS Data Pipeline to refresh users' data.
  • Client's testimonial: "Yes, the event went very well! [...] Thank you for all the hard work you put into making this happen. We couldn’t have done it without you."
Technologies: Freelancing, Amazon Web Services (AWS), AWS Data Pipeline Service, AWS Lambda, Amazon S3 (AWS S3), Node.js, CSS, C#.NET, SQL

Senior Full-stack Developer

2020 - 2020
  • Developed a web service for the new research product, MotivBase AI Ethnography.
  • Implemented NgRx/store on the application that was used to store data inside the complete service.
  • Implemented the mechanism for back and forward buttons, providing the impression that the user is working with a desktop application by restoring pages in the same state as before.
Technologies: Freelancing, NgRx/store, .NET Core, Angular, Node.js, ASP.NET Core, TypeScript, CSS, C#.NET, RxJS, Entity Framework, SQL

GIS Senior Full-stack Developer

2019 - 2020
  • Implemented the feature service, importing geodata from CSV files and storing them in the PostGIS database.
  • Provided visualization in LeafletJS using Proj4Leaflet due to different coordinated systems.
  • Customized and connected with hiding/showing different layers features depending on the zoom levels.
  • Displayed data in a customized way to improve the overall speed of the service.
Technologies: Freelancing, Angular, Leaflet, GeoServer, ArcGIS Server, GIS, TypeScript, CSS, C#.NET, RxJS, Entity Framework, Entity Framework Core, SQL

Desktop Application Developer

2019 - 2020
DivParty, Ltd. (via Toptal)
  • Wrote an installer for a desktop app for both 64 and 32 bit which recognized the Windows version automatically.
  • Reimplemented a (nearly completely rewritten) application due to design changes.
  • Implemented a replay of animated SVG files using chrome browser engine.
  • Designed and laid out according to very precise customer expectations.
  • Integrated a few local email clients with different API and storage system.
Technologies: Freelancing, Amazon Web Services (AWS), Windows Presentation Foundation (WPF), C#, .NET, CSS, C#.NET, SQL

Freelance Full-stack Developer

2018 - 2018
MotivIndex (via Toptal)
  • Refactored an Angular application including implementing architectural changes.
  • Built an NLP library for finding similar words.
  • Introduced very efficient low-level calculation mechanisms based on binary.
  • Prepared Python scripts for manipulation and data transformations.
  • Implemented additional components.
  • Developed new controls based on Canvas: interactive charts supporting panning and zooming, along with sophisticated algorithms to distribute data in a way data are presented reflecting proportions but without overlaps.
Technologies: Freelancing, ASP.NET MVC, Python, Angular, TypeScript, CSS, C#.NET, RxJS, SQL

Freelance Developer (Export Feature and Automated UI Test Suite)

2018 - 2018
MotivIndex (via Toptal)
  • Exported a PowerPoint functionality.
  • Converted charts from SVG to PNG.
  • Automated the tests for the front-end as well as automating the integration tests.
  • Crafted algorithms to retrieve data basing on standard deviation and other calculations.
  • Wrote a set of Python scripts to retrieve data from CSV files and store them inside an SQLite database.
Technologies: Freelancing, Jasmine, C#, Python, Angular, TypeScript, CSS, C#.NET, RxJS, SQL

Angular Developer

2018 - 2018
Stareable | Stareable.com (via Toptal)
  • Was contracted on a redesign project.
  • Implemented changes within the components and UI (HTML and CSS); based on a mock provided by the client.
  • Refactored some part of application making better component division.
Technologies: Freelancing, Angular, TypeScript, CSS, RxJS

Freelance ASP.NET Developer for an eCommerce Site

2018 - 2018
DecoratorsBest (via Toptal)
  • Protected the website against attacks using a WebKnight firewall.
  • Implemented CSS/HTML changes to improve content rendering.
  • Installed JavaScript changes to protect forms against diacritic characters not allowed by third-party services.
  • Developed an MS SQL database trigger to fix diacritic characters problem also on a database level.
  • Implemented changes to the DNS which fixed some older problems.
Technologies: .NET, Freelancing, IIS, C#, ASP.NET, CSS, SQL

Application Development Manager | Scrum Master

2004 - 2018
TECTOCOM Sp. z o.o.
  • Built and designed the application infrastructure and solution security for a portal for external customers to check the order statuses, deliveries, invoices, and more.
  • Crafted a solution to replicate and synchronize data between a productive system and portal, including data and files.
  • Designed, developed, and maintained a system for a huge worldwide company with subsidiaries all over the world, with 3,000+ active users. Distributed file storage, central web application, and numerous desktop application add-ins over many locations.
  • Designed and developed a new application to manage scaffolds for enterprise customers using React and Redux. The app is also developed for mobile devices.
  • Created a concept for the generation of a system, including architecture and organizational approach.
  • Managed the collaborative work over an onion architecture with microservices. Several CAD and Office application plugins were used, involving background services that generated previews and printing in the background.
Technologies: .NET, Visual Basic for Applications (VBA), Service, Office Plugins, CAD, Windows Forms (WinForms), Windows Presentation Foundation (WPF), Windows Communication Foundation (WCF), JavaScript, ASPX, ASP.NET MVC, React, Angular, Visual Basic .NET (VB.NET), CSS, C#.NET, Entity Framework, Entity Framework Core, SQL

Full-stack Developer | Application Development Manager

2000 - 2004
Logotec Engineering S.A.
  • Developed an enterprise document management system for the desktop and web.
  • Installed and set up routines.
  • Maintained, supported, and installed various components and products.
  • Designed parts and implemented software to build mobile applications accessing data from third-party systems.
  • Synchronized the data between a mobile device and the central database.
  • Implemented a local component for access to local databases.
  • Developed specialized controls (an editable data grid) in embedded C++ for Pocket PC.
Technologies: .NET, Embedded C++, Microsoft SQL Server, ASP.NET, Active Server Pages (ASP), C++, C#, Visual Basic for Applications (VBA), VB, Visual Basic .NET (VB.NET), CSS, C#.NET, SQL


Developed application for ethnographic researches. General refactor of whole application many new controls developed from scratch. Including sophisticated chart controls supporting panning and zooming. Developed in Angular with extensive use of canvas. Many algorithms for calculating data with low-level optimization to support processing huge data sets in very short time.

LoadOut Desktop Client Application

Using a legacy codebase, I completely rewrote a Windows WPF .NET application with a sophisticated user interface with a very intuitive and simple navigation system together with auto-update mechanisms. I also implemented the UI with animations along with a detailed logging mechanism using the Chrome engine.

PDM/DDM 9000

This project involved an enterprise document management system. I developed, maintained, and installed the desktop and web versions and customized it for mobile access. I also installed and set up the routines development.


I designed parts and implemented the software to build mobile applications that accessed data from third-party systems. I also synchronized the data between the mobile devices and the central database. I also implemented a local component (access to local databases) and developed specialized controls (editable data grid) in embedded C++ for Pocket PC.


I built a portal for external customers to check their order statuses, deliveries, invoices, and more. I also designed the application's infrastructure and solution security. In addition, I crafted a solution to replicate/synchronize data between a productive system and the MyPERI sytsem (data and files).


I designed, developed, and maintained a system for a huge worldwide company with subsidiaries over the world; I also optimized the system performance. The system had over 3,000 active users, the file storage was distributed over many locations, had a central web application, and numerous desktop parts including application add-ins.


I created a concept for the next generation of systems. I managed the collaborative work over an onion architecture with microservices.

Technologies: Angular, Web API, CQRS, SOLID, IoC, DI, TDD, Pair Programming

Application for Virtual Conference/exhibition Hall

I overtook existing static HTML pages and created an Angular application with a complete administration module, database, and dynamic content pages within a very tight schedule. This serverless application is based on AWS Lambda and S3 hosting.
1990 - 1995

Master of Science Degree in Automatic Control and Robotics

Silesian University of Technology - Gliwice, Poland


Professional Scrum Master II



Professional Scrum Product Owner



Professional Scrum Master I



Microsoft Certified Solutions Developer (MCSD) Certification in Microsoft .NET



Selenium WebDriver, Windows Forms (WinForms), NgRx/store, Entity Framework, React, ASPX, PrimeNG, Selenium Grid, LINQ, REST APIs, RxJS, Leaflet, Node.js


Canvas, Web GIS, Wix Installer, TFS, Git, Jira, qTest Manager, IBM Rational Team Concert (RTC), Visual Studio, CAD, GIS


ASP.NET, ASP.NET Core, Selenium, Angular, .NET Core, ASP.NET MVC, Entity, .NET, Windows Presentation Foundation (WPF), Swagger, Angular Material, ASP.NET Core MVC, Entity Framework Core, SpecFlow, Protractor, Jasmine, Bootstrap


SQL, Less, Sass, HTML5, T-SQL (Transact-SQL), HTML, Visual Basic for Applications (VBA), C#, TypeScript, JavaScript, C#.NET, CSS, Visual Basic .NET (VB.NET), C++, VB, Active Server Pages (ASP), Embedded C++, Python


Database Design, Azure DevOps, Agile Software Development, CQRS, Continuous Integration (CI), Behavior-driven Development (BDD), Test-driven Development (TDD), Domain-driven Development, Test Automation, Event Storming, DevOps, Responsive Web Design (RWD), Pair Programming


Windows, AWS Lambda, Amazon Web Services (AWS), Azure, Visual Studio Code (VS Code), ArcGIS Server


SQL Server 2017, Microsoft SQL Server, PostgreSQL, MySQL, GeoServer, Amazon S3 (AWS S3), AWS Data Pipeline Service, NoSQL


Freelancing, Full-stack, Lightspeed, DI, IoC, Certified Scrum Product Owner (CSPO), SOLID Principles, PSM-1, AWS DevOps, Responsive UI, Lean Development, DevExpress Controls, Windows Communication Foundation (WCF), Professionalism, Domain-driven Design (DDD), Office Plugins, Service, IIS, Performance

Collaboration That Works

How to Work with Toptal

Toptal matches you directly with global industry experts from our network in hours—not weeks or months.


Share your needs

Discuss your requirements and refine your scope in a call with a Toptal domain expert.

Choose your talent

Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.

Start your risk-free talent trial

Work with your chosen talent on a trial basis for up to two weeks. Pay only if you decide to hire them.

Top talent is in high demand.

Start hiring