Jan is a passionate software engineer with 7+ years of experience working on the development of multiple applications, including the implementation of a payment system used by one of the biggest e-commerce groups in Central and Eastern Europe. He is highly-skilled in Python but also keen to learn new tools and technologies, aiming to improve people's lives through technology, creativity, and collaboration.
Performed maintenance for a Fintech app, including online payments processing, credit scoring, data exports, security issues, REST API, admin view, etc.
Implemented a mechanism to sync credit card payments with the database. Designed a REST API and maintained its documentation using Apiary and OpenAPI.
Integrated the system with asynchronous tasks (Celery) communicating with 3rd party apps via API calls.
Acted as a remote contractor delivering a complete end-to-end online sales application process for TOP 10 automobile manufacturers in a very agile startup environment.
Integrated a web application with Salesforce CRM so the sales department could have up-to-date information about the customer order progress.
Wrote custom PostgreSQL queries to speed up the requests. Created microsites and integrated them with Google Tag Manager.
Acted as team leader and main maintainer of the default Fedora Linux system component DNF which keeps customers's machine up-to-date with security patches and lets users install a new software.
Drove change of replacing main system component of Fedora Linux distribution which was hardlymaintainable and so costly for Red Hat. Coordinated the development of the microdnf package manager for RHEL Atomic image so RHEL images having microdnfinside could be 2.5 times smaller.
Maintained the Linux software package manager (Python, C), adding compatibility features, improving package dependency resolution and releasing regular upgrades of DNF package management stack.
The project is a software package manager that installs, updates, and removes packages on RPM-based Linux distributions. I improved the dependency solver and UX of the application to make it more intuitive and attract more users. Optimized the searching for packages to update 50 times faster. The application became the default package manager in Fedora 22 distribution in 2015. The number of active machines using DNF was increased from a few thousand to a few million in 3 years.
The project is a portal enabling end-to-end online car sales for Genesis. I implemented a preorder process for a new Genesis G70 car model and created additional microsites generating leads within a month. After the launch, the number of preorders exceeded the expected number of preorders by 100% within the first month. Performed front-end and back-end implementation of the end-to-end online car sales process on automaker's sites (model selection and customization, scheduling test drive, credit application, trade-in appraisal, customer/dealer/admin view). Integrated system with 3rd party apps via API (Salesforce, Stripe, Canadian Black Book, etc.).
MALL Pay is an online payment service offering users a "buy now, pay later" experience and determining the risk of supplying credit within a few seconds. Verified users are also able to apply for a physical credit card. I implemented a mechanism to sync credit card payments from card issuer with our database. Co-implemented revolving loan application form with background asynchronous credit checks from 3rd parties. Implemented endpoints to be able to perform card and transaction operations from API. Made syncing of the subscribed email list with Mailchimp 8 times faster while taking half memory by optimizing database queries and API calls. Over 30 000 applications of revolving loans were made during the first month after launch.
Education
Master of Engineering - MEng in Intelligent Systems
