PrinceSoft

Przemysław Książek · PrinceSoft

Kotlin developer

I build backend systems, mobile applications and payment integrations. I support teams developing software for fintech, e-commerce and media — from architecture to maintenance.

Kraków & remote · B2B collaboration

Let’s discuss your project Explore my experience
years of experience in IT
8+
backend and Android
Java + Kotlin
collaboration with teams
B2B

01 / Services

How I can help

Support for building new solutions and developing existing systems.

02 / About

Experience that supports your team

My name is Przemysław Książek and I run PrinceSoft. I have over 8 years of experience in IT across fintech, e-commerce and media. I have worked on systems where transaction security, performance and service continuity matter.

I build backend systems and Android applications. My experience includes designing systems from scratch, defining contracts between components, planning architecture and developing existing software.

In senior roles, I have also contributed to defining requirements and allocating tasks. I combine hands-on development with an understanding of how technology serves the needs of a project.

03 / Projects

Selected project experience

Examples of systems I have worked on and the scope of my contribution.

Card systems

Context
Systems for issuing payment cards, managing the card lifecycle and maintaining customer data.
My contribution
System maintenance, improvements to application processing and report generation. Participation in round-the-clock technical support on a shift basis.

Online and mobile banking

Context
An online banking portal with a mobile application and backend systems.
My contribution
Application maintenance, card lifecycle management, BLIK implementation and 3DS authentication.

3DS payment systems

Context
Critical systems for authenticating payment card transactions.
My contribution
Development of 3DS architecture components, including ACS and 3DS SDK, and participation in their certification process.

Samsung — Card Cashback

Context
An Android application for handling discount codes and converting them into mobile payments.
My contribution
Building the application from scratch using the supplied interface design. Google Pay support, integration with card systems and implementation of encrypted communication.

Subscription management

Context
Systems covering subscription creation, invoicing, recurring payments and cancellation.
My contribution
Designing systems and integrations with Zuora and Salesforce. Building a cloud-based microservices architecture and automating deployments.

Technologies and tools

Technologies I have worked with in backend, mobile and cloud projects.

Backend & cloud

  • Java
  • Kotlin
  • Spring
  • Microservices
  • Ktor
  • Kafka
  • RabbitMQ
  • AWS
  • Docker
  • Terraform
  • Convox

Android & data

  • Android
  • Hilt
  • Dagger
  • RxJava
  • Room
  • PostgreSQL
  • Oracle
  • Cassandra

Tools & monitoring

  • GitHub Copilot
  • Cadence
  • Datadog
  • Grafana
  • Unleash
  • GitLab CI/CD
  • SonarQube
  • JUnit 5
  • Detekt

Working together

I work on a B2B basis, in Kraków and remotely. The scope depends on your project: implementation, system development, architectural support or optimization.

Location
Kraków / remote
Engagement
B2B contract
Languages
Polish (native), English (B2)

Contact

Let’s discuss your project

Tell me about your system, its current stage and the support you need. This gives us a useful starting point for discussing the scope of our collaboration.

contact@princesoft.pl

I usually respond within 24 hours.