<pre class="shiki github-dark shaku"><code>type Slice1&lt;T extends string&gt; = T extends `${infer A}${infer B}` ? B : never;type GetFirst&lt;T extends string&gt; = T extends `${infer A}${infer B}` ? A : never;type _CamelCase&lt;S extends string&gt; = S extends `${infer A}${infer B}` ? A extends '_' ? `${Uppercase&lt;GetFirst&lt;B&gt;&gt;}${_CamelCase&lt;Slice1&lt;B&gt;&gt;}` : `${A}${_CamelCase&lt;B&gt;}` : Stype CamelCase&lt;S extends string&gt; = `${Uppercase&lt;GetFirst&lt;S&gt;&gt;}${Slice1&lt;_CamelCase&lt;S&gt;&gt;}`// type A = CamelCase&lt;'big_front_end'&gt; // BigFrontEnd</code></pre>

This is my accepted solution

Implement CamelCase<S> to turn string in snake case to camel case. type A = CamelCase<'big_front_end'> // BigFrontEnd…