\documentclass{beamer}

\setbeamertemplate{navigation symbols}{}

\usepackage{fancyvrb}
\usepackage{adjustbox}
\usepackage{pygments}

\usepackage{tikz}
\usetikzlibrary{arrows}
\usetikzlibrary{fit}
\usetikzlibrary{arrows.meta}
\usetikzlibrary{positioning}

\setbeamersize{text margin left=5mm,text margin right=5mm}
\setlength{\headsep}{-5mm}

\def\hl #1{{\setbox0=\hbox{#1}%
    \adjustbox{set vsize={\ht0}{\dp0}}{\hbox to \wd0{\hss\colorbox{yellow}{#1}\hss}}}}

\def\hl #1{%
  \tikz[overlay,baseline,inner sep=1pt]
    \node[fill=yellow,anchor=text] {\color{yellow}#1};%
  #1%
}

\def\onlyhl #1{\only<#1>\hl}
\def\onlyshow #1{\only<#1>}

\begin{document}

\begin{frame}[t,fragile]
  \vbox to 0pt{%
    \IfFileExists{out.code}{\VerbatimInput[commandchars=\\\{\}]{out.code}}{}
    \vss
  }
  \vbox to \textheight{%
    \vss\IfFileExists{out.tikz}{\input{out.tikz}}{}%
  }
\end{frame}

\end{document}