%%\documentclass[dvisvgm]{minimal}
\documentclass{minimal}

\usepackage{tikz}
\usetikzlibrary{graphs, graphdrawing, shapes.misc}
\usegdlibrary{trees}

\begin{document}

\tikzset{terminal/.style={
    % The shape:
    rectangle,
    rounded corners=3mm,
    minimum size=20mm,
    % The rest
    very thick,draw=black!50,
    top color=white,bottom color=black!20,
    font=\ttfamily},
}

\begin{tikzpicture}
  \graph[tree layout, grow'=right, level sep=10mm] {
    bank [terminal]
    -> {
         { a/"transaction processor"[terminal, orient=right, orient tail=bank]
        -> b/"program runtime"[terminal]
        -> c/"BPF VM"[terminal] }, , , , , , , ,
           d/"accounts-db"[terminal, orient=down, orient tail=bank]
    };
    runtime [draw] // { bank };
    SVM [draw] // { a, b, c }
  };
\end{tikzpicture}

\end{document}
