We expected our bitcoin casino migration to take around 6 weeks. It ended up taking close to 4 months.
Moving ~180K player accounts wasn't the difficult part. The problems were all the data connected to them: about 2.3M transactions, 40K+ active bonuses, affiliate attribution, KYC records and ~12K pending or failed crypto/payment transactions.
The biggest headache was the wallet data. We had balances across BTC, ETH and several stablecoins, and the two platforms handled transaction IDs, exchange rates and pending blockchain deposits differently. Even small discrepancies had to be investigated before we could move a player's balance.
We kept both systems running for roughly 5 weeks and reconciled wallets and transactions daily before switching all traffic.
If you're planning a bitcoin casino migration, don't just ask whether a provider can import your database. Ask specifically about crypto balances, blockchain transaction history, bonuses, VIP levels, affiliate data and wallet reconciliation. Also my advice to you read this article about igaming project migration
https://nuxgame.com/blog/simplifying-platform-migrationLaunching a bitcoin casino is one thing. Moving an active one without messing up player balances is another.