Frontend Engineer - AI-Native Web Experiences

About the role

ActAI builds proactive applications for people who are not used to complex prompting, aiming to bring intelligence to conversations, errands, organisation and workflows with minimal to no prompting. As a Web Frontend Engineer in Warsaw, you will build the core web experiences of Chat, Notes, Calendar, Docs and Sheets, owning complex, highly interactive product surfaces from architecture through implementation.

Key responsibilities

• Build major web experiences across Chat, Notes, Calendar, Docs and Sheets.
• Develop complex interactions such as real-time messaging, collaborative editing, rich-text editing, scheduling, tables and spreadsheets.
• Build reusable frontend architecture and components consistent across ActAI applications.
• Integrate streaming AI responses, proactive actions and model-driven experiences into product workflows.
• Own frontend performance, responsiveness, reliability and accessibility across browsers and devices.
• Work with product and design to turn prototypes into production quickly.

Required profile

• Strong experience building complex, production web applications.
• Experience with highly interactive products such as chat, collaboration, productivity, document editing, calendars or workspaces.
• Able to independently own features from technical design through production.
• Strong product and UI judgment with attention to interaction details.

Required skills

• React and TypeScript
• Frontend architecture, state management, browser APIs and performance
• Real-time systems, WebSockets, streaming APIs or collaborative interfaces
• Next.js, Node.js, REST and GraphQL APIs

The interview process involves 3 to 4 interviews, conducted virtually and/or onsite, with a prompt decision once a fit is found.