Aleš Krajník

Led a cross-functional team of PHP and Frontend engineers, SREs and machine learning specialists, maintaining and innovating the core fraud- prevention system, used across 48 different OLX sites and analysing over 20 Mils. of user actions every day.

Led design and implementation of a behavioural rule-based fraud-prevention system "Fraud Rules", a part of the core anti-fraud system, successfully adopted by local moderator teams. Maintained and innovated the core fraud-prevention system, used across 48 different OLX sites and analysing over 20 Mils. of user actions every day.

Maintained and developed the SellerCenter back-office platform used across various Rocket Internet's ventures.

Ran a company providing web development services with a focus on informational systems. Providing services for companies such as Prague Airport, MEDIA Factory Czech Republic, DC Service, PhotoWorx, PFA Service, virtual-zoom. Focused on complex web projects such as online booking systems with integration to payment systems, backend administration interfaces and web applications.

Implemented product and security features for a SPA frontend of an online banking for J&T Bank.

Led engineering efforts in a renowned Czech web agency. Designed and developed a core CMS platform. Oversaw engineering, website security, hosting and server technologies. Responsible for education and coordination of the engineering team.

Led a team of PHP engineers, responsible for engineering of websites and e-commerce solutions for renowned companies in Czech Republic (Hypoteční banka, Modrá Pyramida). Designed and developed a core CMS platform.