I recently added a search feature to my site. I almost cracked open the Algolia docs … and then I just wrote a 4-line form …

    <form action="https://duckduckgo.com/" method="get">
      <label>▷ <input type="search" id="search" name="q" /></label>
      <input type="hidden" name="sites" value="johnnydecimal.com" />
      <input type="submit" value="Search" style="display: none;" />
    </form>

…and now DDG just does it for me. Zero cost, zero hassle.