The experience our standards are built on
This page describes the professional experience of the company's founder, Jakub Zając. It is written in the first person because it is his own work, not a collective company record.
01Enterprise environments
QA and data reliability at scale
Projects at PwC, Roche and E.ON: test automation, data quality and cloud platforms inside regulated, multi-team organizations.
- UI, API and data test automation (Python, PyTest)
- Data validation and a data reliability platform on AWS
- Working in CI/CD pipelines and formal release processes
- Collaboration with international, distributed teams
02Own products
Apps taken from idea to the app stores
Projects owned end to end: architecture, code, testing, release and maintenance — including the IZAPzoo loyalty platform and the ThomasSeekerAI application.
- Android and iOS apps with a cloud backend
- Admin panels and role-based permission systems
- Releases to Google Play and the App Store
- Maintenance and further development after launch
03Web & automation
Websites, integrations and process automation
Websites and web applications for companies, plus automations that take repetitive manual work off people's plates.
- Company and personal-brand websites
- API integrations and data synchronization
- Python automations and scheduled jobs
- Technical SEO and performance foundations
04Local support
Computer service and IT support in Bydgoszcz
The practical side of IT: from diagnosing a laptop to configuring an entire office — for companies and private clients.
- Computer diagnostics and repair
- Networks, Wi-Fi and printers in homes and offices
- Microsoft 365 and Google Workspace
- Backups and security basics
Organizations whose projects we have worked on
From global corporations to local companies and personal brands. Each of these environments teaches something different about holding quality under pressure — and that is where the standards we bring to every engagement come from.
Enterprise environments
- PwC
- Roche
- E.ON
- Mercedes-Benz
- EBI 24
Client projects
- MentalExpert
- IZAPzoo
- NZOZ Zdrowie
- Kamil Rosikiewicz
Names and trademarks remain the property of their respective owners and appear here for identification only. They indicate organizations whose projects we have worked on — they do not imply endorsement, recommendation or partnership.
Where this work has already held up
Four environments, four different kinds of difficulty — this is where the standards we bring to every engagement come from.
Roche
Conventional testing assumes the correct result is known in advance. With a chatbot and backend LLM services it isn't, so the first job is agreeing what actually counts as a good answer. I lead QA in that area: the team defines the acceptance criteria, and we trace model calls in Langfuse so a bad answer can be followed back to what produced it. With an LLM, 'it looked fine to me' is not a test result.
- Testing a chatbot and backend LLM services
- LLM observability and call tracing (Langfuse)
- Acceptance criteria and answer-quality evaluation
- AI quality in a regulated organization
Testing a system with no single right answer
PwC
A large-scale data modernization and migration program in an enterprise environment. Moving the data is not the hard part; proving that what lands on the other side is exactly what was there before is. I own the QA strategy for the program and build the ETL pipelines on AWS, with validation and reconciliation run in SQL.
- QA strategy for a data modernization and migration program
- ETL pipelines on AWS: S3, Glue, Redshift, PySpark
- SQL-based data validation and reconciliation, data-quality checks
- Working in restricted-access environments with elevated security requirements
Proving the data survived the migration
E.ON Polska
IoT, energy management and metering platforms: central measurement data repositories and meter reading systems. A failing test settles nothing on its own there — the question is still whether the fault sits in the application or in the meter. I led the automated testing strategy for those systems, and some of it stayed manual, because not everything in a system like that fits into a script. I also mentored members of the QA team.
- Automated testing strategy in Python and Selenium
- UI, functional and regression testing of web applications
- API and integration testing with SoapUI
- IoT, energy management and meter reading platforms
Testing IoT and metering platforms
EBI Systems
An enterprise document management platform: ETL workflows for batch and near-real-time processing. I designed, built and maintained those pipelines, and on the quality side I covered the same system. You write a pipeline differently once you are the one who has to break it.
- ETL pipelines: batch and near-real-time processing
- SQL and PL/SQL transformations, processing and validation in Python
- Relational databases and MongoDB, Redis as a caching layer
- API, integration and end-to-end tests (Python, Selenium)
Data pipelines and tests for a document platform
Organization names describe environments in which work was delivered; they do not imply endorsement, recommendation or partnership. Confidential projects are described in anonymized form only.
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