Bedrock model IDs have a short shelf life. New Claude, Nova, and Llama versions land every few months, pricing changes, and yesterday's best pick becomes today's legacy model. If the model ID is hardcoded in your Lambda, every swap is a code change, a review, and a redeploy — and if the new model misbehaves, rolling back is another deploy. In this hands-on, we'll fix that by building a model router where the model choice lives in AWS AppConfig feature flags, not in code. A Lambda behind API G...