_Originally posted by @S3RK in https://github.com/bitcoin/bitcoin/pull/24984#pullrequestreview-952900468_

> With current implementation we don't save the rescan progress and on the next load we will have to start from scratch. Is it possible to save the last processed blocked at shutdown?

It would be nice if wallet code would call `WriteBestBlock` and save the last scan position if it is interrupted during a sync. This could be implemented by trying to save the scan position during the shutdown, or by just periodically saving the scan position after an interval, similar to indexing code which saves sync position once every 30 seconds:

https://github.com/bitcoin/bitcoin/blob/f0a834e2f10a0aa60c7cc76e9f3eb090168a32e5/src/index/base.cpp#L170-L175
{
        
        assert(NotifyUnload.empty());
    }
    bool IsCrypted() const;
    bool IsLocked() const override;
    bool Lock();
    
    bool HaveChain() const { return m_chain ? true : false; }
    /** Map from txid to CWalletTx for all transactions this wallet is
     * interested in, including received and sent transactions. */
    std::map<uint256, CWalletTx> mapWallet GUARDED_BY(cs_wallet);
    typedef std::multimap<int64_t, CWalletTx*> TxItems;
    TxItems wtxOrdered;
    int64_t nOrderPosNext GUARDED_BY(cs_wallet) = 0;
    uint64_t nAccountingEntryNumber = 0;
    std::map<CTxDestination, CAddressBookData> m_address_book GUARDED_BY(cs_wallet);
    const CAddressBookData* FindAddressBookEntry(const CTxDestination&, bool allow_change = false) const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
    /** Set of Coins owned by this wallet that we won't try to spend from. A
     * Coin may be locked if it has already been used to fund a transaction
     * that hasn't confirmed yet. We wouldn't consider the Coin spent already,
     * but also shouldn't try to use it again. */
    std::set<COutPoint> setLockedCoins GUARDED_BY(cs_wallet);
    
    std::unique_ptr<interfaces::Handler> m_chain_notifications_handler;
    
    interfaces::Chain& chain() const { assert(m_chain); return *m_chain; }