Łukasz K.

Balyasny Asset Management is a global multi-strategy investment firm that uses data-driven solutions and advanced technology to support trading and investment decisions.

• Leading the development of internal financial tools and analytics systems, focusing on performance and scalability.
• Collaborating with cross-functional teams to integrate third-party APIs and ensure data reliability.
• Enhancing frontend performance and developer tools with a modern React and TypeScript stack.
• Supporting architectural evolution and mentoring mid-level engineers on best practices.

Frey is a digital car leasing and vehicle management company offering web and mobile solutions for B2C/B2B users.

• Modernized the frontend infrastructure and improved the performance of critical features, including document upload and form rendering.
• Developed and integrated a document management system with AWS services.
• Built backend microservices in Node.js for PDF manipulation and Excel file parsing.
• Acted as frontend lead, mentoring team members and coordinating work across frontend and backend teams.

Walnut is a platform for B2B sales representatives to create interactive product demos and measure engagement.

• Developed UIs in React for an application tailored to business sales representatives, enabling them to create interactive product demos and track their impact on sales opportunities.
• Maintained and expanded GraphQL APIs in Elixir, integrating with third-party services, and authored unit and end-to-end (E2E) tests for the application.
• Took on leadership responsibilities, leading retrospective meetings, initiating cross-team projects, drafting RFCs, and developing leadership skills.

Goldman Sachs is a global investment bank providing financial services in trading, asset management, and securities.

• Contributed to the development of a trader-focused application for Commodities and FX orders, optimizing React components for real-time processing of large datasets.
• Managed the development of algorithmic FX order functionality on the frontend.
• Applied event-driven design principles using WebSockets, RxJS, and MobX to build robust, real-time user interfaces.
• Performed unit and end-to-end (E2E) testing for the application.
• Gained domain knowledge in the banking industry, with a focus on currency exchange.

Worked via ITDS Business Consultants for internal HR and business automation tools on the ServiceNow platform.

• Worked as a JavaScript developer on the ServiceNow platform.
• Contributed to the development of internal HR and business process automation tools.
• Used Angular.js to create UIs and integrate them with ServiceNow’s backend, forms, and other components.

Togedo is an EdTech platform offering NLP-based learning experiences and custom LMS platforms.

• Developed and optimized React applications. Created and maintained GraphQL APIs on a Node.js server.

• Developed a large-scale NLP model in Python.

• Implemented unit, integration, and E2E tests using Jest and Cypress.

eBay is one of the world’s largest online marketplaces.

• Efficiently handled a high volume of customer inquiries, returns, and disputes, providing exceptional support to German-speaking clients;

• Demonstrated strong communication and problem-solving skills by effectively resolving issues and ensuring a high level of customer satisfaction;

• Contributed to team efforts by maintaining detailed records of customer interactions and identifying trends to help improve the overall service process.