We build a self-contained data compressor and decompressor from scratch. The compression scheme is based on Huffman coding, which is used in gzip, zip, and many other compression formats. No prior knowledge of Huffman coding or data compression is necessary. The source code, including helper files not shown in the screencast, is available at https://github.com/garybernhardt/destroy-all-software-extras/tree/master/das-0102-data-compressor-from-scratch