Founded in 2012, wikifolio.com is a dynamic and rapidly growing FinTech in Vienna and the best-known company for B2C investments in German-speaking countries.

We believe that everybody should be able to invest successfully in the capital markets – regardless of whether you have €100 or €100,000 to invest. We stand for the democratisation of the investment market and put our users at the centre of our focus.

Build high-performance web applications, work with real-time financial data, and shape the user experience of modern investing – join us as a Senior Front-End Developer.

Responsibilities

• Develop, maintain, and optimize modern web applications using JavaScript (ES6+), HTML, and CSS.
• Build scalable, reusable, and maintainable UI components and front-end architectures.
• Design responsive, accessible, and high-performance user interfaces.
• Write clean, modular, and well-documented code following best practices and coding standards.
• Conduct thorough code reviews and provide constructive feedback to ensure high code quality and performance.
• Collaborate closely with designers, backend engineers, and product stakeholders to translate business requirements into robust UI solutions.
• Contribute to the full software development lifecycle (SDLC), from requirements and design through deployment and monitoring.
• Implement unit, integration, and end-to-end tests.

• Identify and resolve performance bottlenecks (e.g., rendering, bundle size, network issues).
• Optimize applications for speed and scalability (e.g., lazy loading, code splitting).
• Stay up to date with evolving front-end technologies, frameworks, and browser APIs.
• Advocate for best practices in UX, performance, and maintainability.

Requirements

• Strong JavaScript expertise, including a deep understanding of:
• • JavaScript fundamentals
  • ES6+ features (closures, promises, async/await, modules)
  • Prototypal inheritance
  • Functional programming concepts
• Deep understanding of browser internals, including:
• • Event loop, call stack, task queue, microtasks
  • Rendering pipeline (reflow, repaint, compositing)
• Strong knowledge of HTML5 and semantic markup
• Advanced understanding of CSS, including:
• • Cascading and specificity
  • Layout systems (Flexbox, Grid)
  • Responsive design
  • Animations and transitions
• Production experience with React 17+/18, including hooks, context, composition patterns, error boundaries, and performance optimization (memoization, lazy loading, code splitting)
• Understanding of both server state (e.g., React Query, SWR) and client state (e.g., Valtio, Zustand, Redux)
• Experience integrating REST APIs
• Strong understanding of web performance optimization techniques
• Experience with CI/CD pipelines, including Docker builds, branch-based deployment strategies, and environment variable management across environments (dev/staging/prod)
• Experience with testing frameworks (e.g., Jest, Vitest, Cypress, Playwright)
• Proficiency with CSS-in-JS solutions (e.g., Emotion, Styled Components), including theming, dynamic styles, and SSR style injection
• Strong problem-solving skills and attention to detail
• Fluency in English (written and spoken), along with excellent communication skills and the ability to collaborate effectively in international teams

Nice to Have

• Experience with TypeScript and strong typing patterns
• Familiarity with SSR/SSG frameworks (e.g., Next.js, Nuxt)
• Experience with design systems and component libraries
• Knowledge of Progressive Web Apps (PWAs)
• Familiarity with Azure (especially Front Door and storage for static assets)
• Basic understanding of backend concepts (APIs, authentication flows, microservices)
• Experience with monitoring tools (e.g., Dynatrace)

The minimum monthly salary for this position is €4,476 gross, in accordance with the IT-collective agreement, however the salary we offer will be adjusted in line with the successful candidate’s qualifications and experience.