LeanCode

LeanCode is a software development company based in Warsaw, Poland, with 80+ employees and 40+ dedicated Flutter developers. Since its founding, the company has delivered 100+ digital products, primarily for enterprise and scale-up clients across banking, fintech, HR tech, healthcare, and other sectors. The team focuses heavily on Flutter—cross-platform mobile and desktop development—alongside .NET and React expertise. LeanCode handles the full product lifecycle, from initial scoping through launch and long-term support.

Services and capabilities

LeanCode structures its offerings across three phases. In Discovery, the team runs free scoping workshops, design thinking sessions, UX/UI design, IT consulting, and mobile app audits to help clients validate concepts and reduce project scope creep. For Delivery, they offer mobile app development, web app development, custom software, staff augmentation, and specialized Flutter UI testing via Patrol automation. In the Growth phase, they provide AI transformation consulting, Flutter training, 24/7 support with SLAs, DevOps and infrastructure services, and Patrol setup.

Flutter is the core technology. LeanCode also works with .NET (which they describe as "cross-platform," running on macOS, Linux, and Windows) and React (highlighting its 119K+ library ecosystem and performance for single-page applications). On the delivery side, the team has built projects using Node.js, Xamarin, and integrations with external backends for real-time data sync.

Notable work

Credit Agricole Bank Polska (CA24 Mobile): One of LeanCode's marquee projects. The team built CA24 Mobile, described as "one of the biggest Flutter applications in the world." Thirty Flutter developers worked for 12 months, with 200+ team members involved over the full year. The app delivers digital banking to retail customers and is noted for offering "a customer experience and user interface which are unique on the Polish market." The Deputy CIO attested the team delivered the MVP in 2.5 months, exceeding expectations, and praised their understanding of the banking industry.

Ride (Caretaker): A mobility SaaS for car rental and fleet management. LeanCode delivered a feature-rich mobile app in 4 months. The platform includes virtual keys for app-based vehicle access, fleet management, and backend integration. It operates at 100+ rental locations across Switzerland.

Wedel Chocolate Factory (Kiosk App): LeanCode created an interactive AI-powered Flutter Desktop app for Wedel's museum. Ten remotely managed kiosks let visitors design custom chocolate packaging with a curated AI image database. The app was built in 6 months and saw 350K visits in its first year at the museum.

Welliba: An Employee Experience Management System (ExMS) integrating behavioral science. LeanCode built a platform available in 7 markets, with 4 separate web applications for different feature sets. The engagement spans 3+ years and counting.

Other completed projects include Prospector (sales lead platform), Kontomierz (fintech expense categorizer), Invoice Gateway (payment settlement), Mindy (mindfulness app), GastroJob (hospitality recruitment), and over a dozen more spanning healthcare, sports, education, and food tech.

How they work

LeanCode operates on fixed-price projects, time-and-materials, and staff augmentation models. The initial engagement typically starts with a scoping call with one of their senior engineers or the CEO (Łukasz Kosman) to define feasibility and provide ballpark estimates. Clients consistently report professional project management, clear communication, and well-organized processes. The company publishes proprietary frameworks—a 21-step Flutter migration roadmap and an enterprise Flutter best-practices guide based on projects involving 20+ developers—suggesting a process-driven approach.

Team and credentials

LeanCode has 80+ employees total, 40+ of whom are dedicated Flutter specialists. The CEO is Łukasz Kosman. The company holds a 5.0 rating on Clutch with reviews from clients including Google (Abdallah Shaban, Outbound Product Manager), Credit Agricole Bank Polska (Tomasz Czerwiński, Deputy CIO), and NOS (Fernando Oliveira, Head of Technology). All three reviews emphasize on-time delivery, technical expertise in Flutter and Dart, professionalism, and responsiveness. The company is based in Warsaw, Poland, and operates within EU data protection frameworks (they mention GDPR compliance on their site).