About
Hi, I'm Krzysztof Janiec
Software engineer crafting elegant solutions and sharing insights on modern web development, architecture, and best practices.
Senior Software Engineer
B2B Contractor • Remote Specialist
I'm Krzysztof Janiec, a passionate senior software engineer based in Poland with over 12 years of experience in full-stack application development and systems architecture. I specialize in building highly scalable, performant, and maintainable solutions across diverse business domains.
Currently, I operate in the e-commerce space, but my professional career spans high-density IoT systems, comprehensive ERP solutions (covering finance, logistics, and supply chain), and various other demanding industries. I thrive on solving complex backend architectures and designing seamless, performant user interfaces.
⚙️ Work Style & Professional Model
Remote-First by Design: I work 100% remotely by choice. My dedicated home office setup is fully optimized for maximum ergonomics and productivity, featuring multiple high-resolution displays and a treadmill desk to stay active and focused throughout the day. If remote collaboration is a deal-breaker for your team, we might not be the best fit. 😉
B2B Contractor Only: I operate exclusively as an independent contractor under a B2B model (with standard tax invoicing). Traditional employment contracts (UoP) are not an option for me, as this setup allows me to offer maximum professional agility, focus, and target-driven partnership. 🤝
Product Creator at Heart: I don't just write code for clients; I design, build, and launch my own independent products. True to the tagline 'building elegant products', this hands-on experience with the complete product lifecycle—from UX and system architecture to marketing and scaling—gives me a holistic owner mindset that benefits every project I join. 🚀
My verified skills and commercial experience are detailed below.
Experience
Where I've worked
Software Developer at AMB Software / REWE Digital Poland
Jul 2024 – Present
Context: Enterprise e-commerce / retail software development
Responsibilities
- Development and maintenance of enterprise-grade applications in the retail/e-commerce domain.
- Backend and frontend feature implementation using Java, Spring Boot, TypeScript and Angular.
- Work with distributed systems, APIs, databases and integrations.
- Cooperation with remote, cross-functional teams in a B2B contractor model.
- Participation in technical analysis, implementation planning, code reviews and delivery.
- Contribution to maintainable, scalable and production-ready software.
Key Deliverables
- Backend services and business logic implemented in Java/Spring Boot.
- Frontend modules and UI features implemented in Angular/TypeScript.
- API integrations and improvements to existing enterprise systems.
- Refactored, tested and maintainable production code.
- Technical support for ongoing product development and system evolution.
Software Engineer at BIOT Sp. z o.o.
Jul 2019 – Jun 2024
Context: IoT platform, microservices and high-density data systems
Responsibilities
- Development of an IoT platform based on microservices architecture.
- Backend development using TypeScript, Node.js, Express/NestJS and related technologies.
- Frontend development using React, Material UI, MobX and mapping/data visualization libraries.
- Design and implementation of APIs using REST, GraphQL and gRPC.
- Work with asynchronous communication and event-driven components using RabbitMQ.
- Database design and development with PostgreSQL, TypeORM and Elasticsearch.
- Implementation of map-based and geospatial interfaces using Mapbox GL and Deck.gl.
- Collaboration on deployment and infrastructure topics using Docker and Kubernetes.
Key Deliverables
- Microservices for IoT data processing and business workflows.
- Web application features for monitoring, management and visualization.
- API layers for frontend/backend and service-to-service communication.
- Database models, queries and persistence layers.
- Real-time or near-real-time data-driven UI components.
- Map-based dashboards and visualizations.
- Production-ready features delivered in a remote B2B setup.
Software Developer Java at Cinkciarz.pl
Nov 2015 – Jun 2019
Context: Financial technology, microservices and business applications
Responsibilities
- Backend development in Java-based microservice systems.
- Implementation of REST APIs and business logic using Java, Spring Boot and Hibernate.
- Development and maintenance of frontend modules using Angular.
- Database integration and persistence layer implementation.
- Work with Docker-based development and deployment workflows.
- Participation in code reviews, debugging, refactoring and production support.
- Collaboration with product, QA and backend/frontend teams.
Key Deliverables
- Java/Spring Boot microservices.
- REST APIs and backend business features.
- Database integrations and Hibernate-based persistence logic.
- Angular frontend modules and UI features.
- Dockerized application components.
- Refactored and maintainable production code.
ERP Developer at TRAX S.A.
Oct 2013 – Oct 2015
Context: ERP systems, business processes and database-driven applications
Responsibilities
- Development and customization of ERP functionality in Infor CloudSuite / Syteline.
- Programming business logic and internal tools using Visual Basic.
- Database development and reporting using MS SQL Server / T-SQL.
- Support for business processes related to ERP, finance, logistics and supply chain.
- Maintenance, debugging and improvement of existing ERP modules.
Key Deliverables
- ERP customizations and business-process extensions.
- SQL queries, reports and database procedures.
- Internal tools supporting operational workflows.
- Bug fixes, enhancements and system maintenance.
- Technical support for ERP users and business stakeholders.
Education
Where I studied
Second cycle of studies - Computer Science
University of Zielona Góra, 2012 - 2014
First cycle of studies - Computer Science
University of Zielona Góra, 2007 - 2011
Skills