Desktop applications
Tools for Windows, macOS, and Linux, from internal software to high-performance products in Rust or .NET where speed and reliability matter.
Building products and software since 2018
Software that
Software that
actually works
for your business.
Klementewicz Development is Jakub Klementewicz’s studio focused on desktop, web, mobile, and game development. I build products end-to-end: architecture, UX, implementation, rollout, and long-term maintenance.
- 500,000+
- people using Schoolovo
- 8+
- years building products and software
- 4
- platforms covered: web, mobile, desktop, games
Jakub Klementewicz · Founder
About
I build software from product idea to stable production.
I am a software engineer and founder. I design architecture, ship backend and frontend code, run deployments, and make sure the product stays reliable after launch instead of falling apart under real traffic.
My work spans education products, business systems, mobile apps, desktop tools, and games. I combine product thinking with engineering execution: UX, APIs, payments, Apple and Google integrations, performance, security, and operations.
Schoolovo is the best-known example, but my earlier public work also covered business-oriented products and game prototypes. That mix translates well into SaaS, B2C products, and technically demanding delivery work.
- Rust / Node.js / Java / PHP / C#
- React / Next.js / Unity / React Native
- PostgreSQL, Cassandra, MariaDB, Redis
- Docker, Kubernetes, k3s, CI/CD, observability
I design and deliver applications that are meant to stay fast, maintainable, and production-ready.
Web apps and SaaS
Customer portals, B2B systems, admin panels, subscription apps, and products with payments, integrations, and operational tooling.
Mobile applications
iOS and Android apps built with React Native or native integrations where login, IAP, push, offline mode, or analytics are critical.
Games and interactive products
Unity-based mobile and desktop games, gameplay prototypes, in-game economy, backend services, and live operations support.
What kind of applications do I build most often?
Education products and large-user platforms
Applications that need real accounts, real traffic, content, subscriptions, and consistent product evolution over time.
Dashboards, internal systems, and business software
Workflow tools, reporting, admin panels, data operations, and integrations with existing company infrastructure.
Mobile apps with accounts, payments, and notifications
Consumer and business apps shipped through the App Store and Google Play, including subscriptions and synced data flows.
Unity games and product prototypes
From proof-of-concept and vertical slice to backend integration, telemetry, and post-launch iteration.
Case study
See Schoolovo →
Schoolovo - my own product used by more than 500,000 people.
Schoolovo is my own product, which I design, build, and operate end-to-end: a Rust backend, a React Native mobile app, integrations, infrastructure, and release flow. It is the kind of product that forces both engineering quality and operational discipline.
That experience carries over into client work: better architecture decisions, more predictable delivery, less improvisation, and fewer expensive mistakes made under pressure.
500,000+product users
Rust + React Nativeown backend and mobile app
End-to-endfrom product work to rollout and operations
Notes from building products, infrastructure, and real-world software.
All posts →The first posts will appear here soon.
Contact
Describe the project. I will reply with specifics.
Tell me what you are building, what stage you are at, and what kind of help you need: MVP, a new product version, an audit, deployment, or long-term development support.
Prefer to start with a short conversation?
We can start with a concise description of the goal and the problem, then pick the right technology and scope.
Email me directly