I built a dashboard to compare mortgage rates across 120 credit unions

When I bought my home, the big bank I'd been using for years quoted me 7% APR. A local credit union was offering 5.5% for the exact same mortgage.I was surprised until I learned that mortgages are basically standardized products – the government buys almost all of them (see Bits About Money: https://www.bitsaboutmoney.com/archive/mortgages-are-a-manuf...). So what's the price difference paying for? A recent Bloomberg Odd Lots episode makes the case that it's largely advertising and marketing (https://www.bloomberg.com/news/audio/2025-11-28/odd-lots-thi...). Credit unions are non-profits without big marketing budgets, so they can pass those savings on, but a lot of people don't know about them.I built this dashboard to make it easier to shop around. I pull public rates from 120+ credit union websites and compares against the weekly FRED national benchmark.Features:- Filter by loan type (30Y/15Y/etc.), eligibility (the hardest part tbh), and rate type - Payment calculator with refi mode (CUs can be a bit slower than big lenders, but that makes them great for refi) - Links to each CU's rates page and eligibility requirements - Toggle to show/hide statistical outliersAt the time of writing, the average CU rate is 5.91% vs. 6.23% national average. about $37k difference in total interest on a $500k loan. I actually used seaborn to visualize the rate spread against the four big banks: https://www.reddit.com/r/dataisbeautiful/comments/1pcj9t7/oc...Stack: Python for the data/backend, Svelte/SvelteKit for the frontend. No signup, no ads, no referral fees.Happy to answer questions about the methodology or add CUs people suggest.