Bartłomiej Krawczyk
Full-Stack Software Engineer
Warsaw, Poland +48 691 177 733 bartlomiejkrawczyk.github.io bartlomiejkrawczyk bartlomiejkrawczyk01@gmail.com
About
Backend-leaning Full-Stack Software Engineer with strong expertise in Kotlin and Java, specializing in cloud-native, distributed, data-centric systems. Proven experience building and operating metadata-driven platforms, ETL pipelines, and scalable backend services in production. Holds a Master's degree in Computer Science with a strong foundation in distributed systems, algorithms, and optimization.
Work Experience
Sages | Software Engineer
July 2023 - Now- Led backend architecture and implementation of Uniplaner, a university class scheduling system, including scheduling logic, conflict detection, real-time updates, and high-performance data access.
- Backend developer on the Knowledge Base platform and related integrations.
- Developed and maintained services within a microservice-based employee evaluation system, contributing to security integration (CAS), ETL job orchestration on Apache Flink, and gateway services.
- Built and evolved client-facing features such as embeddable widgets and metadata export interfaces for external systems, allowing other platforms to harvest structured academic data from the Knowledge Base.
- Focused on performance, scalability, and reliability in production systems.
- Java
- Kotlin
- SQL
- Scala
- Groovy
- Bash
- CSS
- HTML
- JavaScript
- TypeScript
- Spring
- Helidon
- Micronaut
- Ktor
- Hibernate
- Jakarta EE
- React.js
- CI/CD
- Infrastructure as Code
- WCAG
- REST API
- gRPC
- CQRS
- Amazon S3
- Docker
- Kubernetes
- Puppet
- Jenkins
- Bitbucket Pipelines
- Grafana
- Kibana
- Prometheus
- Swagger
- Apache Spark
- Apache Flink
- Apache Solr
- RabbitMQ
- Apache Kafka
- CAS
- Hazelcast
- NGINX
- Apache
- MongoDB
- ArangoDB
- PostgreSQL
- Oracle Database
- MySQL
Sages | Junior Software Engineer
June 2022 - June 2023- Delivered multiple external integrations for the Knowledge Base platform (OAI-PMH, Scopus, USOS).
- Designed and implemented a standardized ETL framework that reduced boilerplate and significantly shortened development time for new integrations.
- Implemented large file support with Amazon S3, introducing streaming-based processing and presigned uploads to handle multi-GB files efficiently.
- Contributed to maintenance and evolution of enterprise academic systems.
- Java
- SQL
- Scala
- Groovy
- Bash
- CSS
- HTML
- JavaScript
- Spring
- Helidon
- Micronaut
- Hibernate
- Jakarta EE
- React.js
- CI/CD
- Infrastructure as Code
- WCAG
- REST API
- CQRS
- Amazon S3
- Docker
- Puppet
- Jenkins
- Bitbucket Pipelines
- Swagger
- Apache Spark
- Apache Solr
- CAS
- Hazelcast
- NGINX
- Apache
- MongoDB
- ArangoDB
- PostgreSQL
- Oracle Database
- MySQL
Education
Warsaw University of Technology February 2024 - September 2025
Master's Degree | Computer Science | Intelligent Systems
Graduated with distinction. Academic average 4.92/5.0.
- Reliable, Scalable, and Maintainable IT Systems
- Parallel and Distributed Programming
- Systems Architecture and Integration
- Algorithms and Optimization Methods
- Mathematical Modeling
- Virtual Computing Environments
Warsaw University of Technology October 2020 - February 2024
Bachelor's Degree | Computer Science | Software Engineering
Graduated with distinction. Academic average 4.96/5.0.
- Algorithms and Data Structures
- Operating Systems
- UNIX System
- Object-Oriented Programming
- Databases
- The Art of Software Development
- Artificial Intelligence
- Machine Learning Engineering
- Deployment and Maintenance of IT Systems
- Network Programming
- Programming Paradigms
- Web Application Programming
- Compilation Techniques
Skills
Languages
Frameworks
Technologies
- Linear Programming
- Functional Programming
- Mixed Integer Programming
- Microservices
- Distributed Systems
- Observability
- Docker
- Kubernetes
- CI/CD
- Testing
- Amazon S3
- Infrastructure as Code
- Domain Driven Design
- REST API
- gRPC
- CQRS
- Event Sourcing
- Domain Specific Language
- Replication
- Load Balancing
- Circuit Breaker
- Service Discovery
- Service Registry
- OAuth 2.0
- Role Based Access Control
- One-Time Password
- WCAG
- GraphQL
- Artificial Intelligence
Tools
- Ansible
- Puppet
- git
- Makefile
- Jenkins
- Github Actions
- Bitbucket Pipelines
- GitLab CI/CD
- NGINX
- Apache
- SSH
- RabbitMQ
- Apache Kafka
- Apache Solr
- Apache Spark
- Apache Flink
- Elasticsearch
- CAS
- Hazelcast
- Prometheus
- Grafana
- Kibana
- Filebeat
- Logstash
- Keycloak
- Liquibase
- 3D printing
- Open API
- Swagger
- Kernel-based Virtual Machine
Operating Systems
Libraries
- Spring Boot
- Spring Data
- Spring Security
- Spring Cloud
- Spring MVC
- Spring WebFlux
- Project Lombok
- Pandas
- PySpark
- PyTorch
- Scikit-learn
- Keras
- NumPy
- Matplotlib
- Tailwind CSS
- Expressive Code
- Playwright
- Rehype
- Remark
- Deep Java Library
- OpenCV
- JetBrains Exposed
- OR-Tools
- AndroidX
- Material Components for Android
- Play Services Vision
- Retrofit
- Burn
- Rayon
- Room
Databases
Linguistics
Projects
- End-to-end academic scheduling platform for universities, providing automated timetable generation, real-time collaboration, and deep integration with institutional management systems.
- Distributed microservice-based platform for automating employee evaluation processes at universities, integrating data from multiple institutional systems and executing large-scale analytical workflows.
- Architected and engineered a fault-tolerant, cloud-native distributed forum platform built on Kotlin/Spring to demonstrate real-world patterns for scalable backend systems. The system employed Microservices, CQRS (Command Query Responsibility Segregation), and Event Sourcing (AXON Framework) to ensure high data consistency and horizontal scaling. Implemented Kubernetes orchestration, automated CI/CD (GitHub Actions), and production-grade features like centralized logging, full observability (Prometheus, Grafana, Kibana), and OAuth 2.0/RBAC identity management. The architecture featured advanced distributed patterns, including Replication, Load Balancing, Circuit Breakers, Service Discovery, and Service Registry.
- Developed a scheduling and optimization platform designed to efficiently assign matches, fields, and referees, demonstrating the practical application of advanced computer science principles. Implemented Mixed Integer Programming (MIP) using Google OR-Tools to solve complex constraints and optimize resource allocation. The solution was secured via a high-performance Kotlin/Spring API utilizing OAuth 2.0 and Role Based Access Control (RBAC) and deployed using Docker.
- Engineered a full-stack generalized board-game AI project that implements and rigorously compares several advanced decision-making algorithms across multiple games and rule sets, not limited to standard chess. The work includes in-depth analysis of algorithmic complexity, practical performance, and gameplay strength. The solution integrates Java, Kotlin and the Deep Java Library (DJL) for core AI logic and leverages Apache Spark/PySpark for large-scale data analysis and evaluation of search and evaluation techniques. The project culminated in a fully playable Android application that allows users to compete against a strong computer opponent across supported games and variants.
- Official Grupa Polsat mobile app for mOTP one-time password generation. Deployed company-wide and trusted by employees, with more than 10,000 downloads.
- Developed a predictive model to identify users most likely to purchase premium subscriptions on a music platform. Leveraged feature engineering, XGBoost with randomized search, and A/B testing to optimize ROC AUC performance.
- During a one-week course in Madrid, I combined technical learning with cultural exchange in an English-taught program. I developed a rotating lidar radar system using Arduino and Processing. The project explored real-time spatial measurement and interactive visualization.
- A high-school engineering project where we built a miniature satellite inside a soda can-from electronics and sensors to the flight computer, and recovery system. Our four-person team developed all software and hardware ourselves, gaining early hands-on experience with full end-to-end engineering.
- This engineering thesis project delivers a full mobile application and backend ecosystem enabling real-time online gameplay for chess, checkers, and fully custom rule-based board games. The system supports dynamic board sizes, non-standard shapes, multiple players, and user-defined rules-all backed by a reactive cloud-based architecture.
- Data analytics and reporting project for the higher education domain, focused on large-scale data processing, statistical analysis, and performance optimization of analytical workloads.
- A research-driven project exploring AI strategies for the Dots game, combining Rust-based algorithm implementations with a web interface and Python analytics. The work evaluates MCTS and MiniMax variants across thousands of simulations, offering insights into search efficiency on large and dynamic boards.
- AM, B, and B1 license holder and active driver since 2019, experienced with both automatic and manual vehicles.
- Integration layer and ETL framework for connecting the Knowledge Base platform with multiple external academic and institutional systems.
- Core enterprise product for aggregating, managing, and exposing university research information, integrating data from multiple internal and external systems into a unified research knowledge platform.
- A Kotlin DSL for defining and solving Linear and Mixed Integer Programming problems with Google OR-Tools, inspired by AMPL-style modeling.
- Design and implementation of large file handling and Amazon S3 integration for a data-intensive university platform, focusing on scalability, streaming-based processing, and system-wide performance improvements.
- One of my early large projects: a platform for connecting people needing help with everyday tasks to local providers. I designed and built the backend and Android app, gaining practical experience with REST APIs, mobile architecture, and shipping real user-facing features.
- Minimalist portfolio achieving perfect 100/100 Lighthouse scores, built with Astro.js/TypeScript. Key features include 10 dynamic color themes, full WCAG compliance, advanced Markdown (LaTeX/Mermaid.js) rendering, and a unique command-line interface for navigation.
- A full interpreter for a custom programming language, built from scratch with a lexer, parser, AST model, and runtime visitor-based interpreter-complete with configurable limits and robust error handling.
- Wordle Clone is a full-stack web application recreating the popular word-guessing game. The project features secure user authentication (OAuth2 + JWT), multi-language word sets, persistent game sessions, and a responsive UI with both light and dark themes.
- A comprehensive introduction to core AI techniques, completed with near-perfect marks. The project explores foundational methods such as evolutionary algorithms, supervised learning, and neural network training.
- A hands-on high-availability system exploring practical distributed systems, automation, and fault-tolerant infrastructure design. The project implements a multi-host cluster running stateless services on lightweight KVM virtual machines, managed by custom Kotlin-based controllers and orchestrated using SSH and Ansible.
- Spring Petclinic Deployment Automation - A DevOps project demonstrating three approaches to automated application deployment: Bash scripting, Ansible IaC, and Kubernetes orchestration.
Certifications
Warsaw University of Technology
Warsaw University of Technology
Association of Academic Centers for Foreign Language Teaching in Poland
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