II
Built to survive a bad API
The interesting engineering in this one is not the packs. It is staying up.
The Pokémon TCG API is unreliable in a way that is hard to design around: measured at roughly a 29% success rate over fourteen consecutive calls on one ordinary afternoon, failing fast with 500s and dropped connections rather than timing out cleanly.
So the app retries hard, and then it remembers. Set lists and slimmed card pools are cached on your device for thirty days, which means that after one good load it keeps working with the API completely dead. That is the difference between a toy and something a kid can actually open on a Saturday.
- Six-tier rarity ladder
- Common through to the modern chase rarities, weighted per era.
- Five pack structures
- Base, e-Card/EX, Diamond & Pearl, Sun & Moon and modern — each with its own slot layout.
- A Dex that fills up
- What you have pulled, tracked across sets and generations.
- Works offline after one load
- Cached pools mean the app opens and runs without the network once it has seen a set.