You mentioned UI-kit. What component was the most complex or interesting to implement, and which posed the biggest challenge?

The most challenging and interesting component in implementing the UI-kit for me was a dynamic table with editing and sorting capabilities. The main difficulties included:

• Ensuring high performance with a large number of rows and columns.
• Supporting various data types in cells (text, numbers, dates, checkboxes) with appropriate editors.
• Implementing a user-friendly UX: sorting, filtering, pagination, row highlighting.
• Ensuring accessibility for users with disabilities.

The challenge was to make the component as versatile and customizable as possible so that it could be used in different projects with minimal changes. It was also necessary to think through the architecture to easily add new cell types and functions.

An example of a simplified React component for a sortable table:

function SortableTable({ data, columns }) {
  const [sortKey, setSortKey] = React.useState(null);
  const [sortAsc, setSortAsc] = React.useState(true);

  const sortedData = React.useMemo(() => {
    if (!sortKey) return data;
    return [...data].sort((a, b) => {
      if (a[sortKey] < b[sortKey]) return sortAsc ? -1 : 1;
      if (a[sortKey] > b[sortKey]) return sortAsc ? 1 : -1;
      return 0;
    });
  }, [data, sortKey, sortAsc]);

  const onHeaderClick = key => {
    if (sortKey === key) {
      setSortAsc(!sortAsc);
    } else {
      setSortKey(key);
      setSortAsc(true);
    }
  };

  return (
    <table>
      <thead>
        <tr>
          {columns.map(col => (
            <th key={col.key} onClick={() => onHeaderClick(col.key)}>{col.title}</th>
          ))}
        </tr>
      </thead>
      <tbody>
        {sortedData.map((row, i) => (
          <tr key={i}>
            {columns.map(col => <td key={col.key}>{row[col.key]}</td>)}
          </tr>
        ))}
      </tbody>
    </table>
  );
}

This example illustrates the basic sorting logic, but the actual component was much more complex and included editing, validation, and other features.