Event Sourcing — что это и когда применять?

public sealed class Account
{
    public Guid Id { get; private set; }
    public decimal Balance { get; private set; }
    public bool IsClosed { get; private set; }
    public int Version { get; private set; }

    private readonly List<object> _uncommitted = [];
    public IReadOnlyList<object> UncommittedEvents => _uncommitted;

    // Восстановление состояния из истории
    public static Account Rehydrate(IEnumerable<object> history)
    {
        var account = new Account();
        foreach (var e in history) account.Apply(e);
        return account;
    }

    // Команды: проверяют правила и порождают события
    public void Withdraw(decimal amount)
    {
        if (IsClosed) throw new DomainException("Счёт закрыт");
        if (amount > Balance) throw new DomainException("Недостаточно средств");
        Raise(new MoneyWithdrawn(Id, amount, DateTimeOffset.UtcNow));
    }

    private void Raise(object e) { Apply(e); _uncommitted.Add(e); }

    // Apply: только изменение состояния, без проверок и побочных эффектов
    private void Apply(object e)
    {
        switch (e)
        {
            case AccountOpened o: Id = o.AccountId; break;
            case MoneyDeposited d: Balance += d.Amount; break;
            case MoneyWithdrawn w: Balance -= w.Amount; break;
            case AccountClosed: IsClosed = true; break;
        }
        Version++;
    }
}

public sealed record AccountOpened(Guid AccountId, string Owner, DateTimeOffset At);
public sealed record MoneyDeposited(Guid AccountId, decimal Amount, DateTimeOffset At);
public sealed record MoneyWithdrawn(Guid AccountId, decimal Amount, DateTimeOffset At);
public sealed record AccountClosed(Guid AccountId, DateTimeOffset At);

CREATE TABLE events (
    global_position bigserial PRIMARY KEY,
    stream_id       text        NOT NULL,
    version         int         NOT NULL,
    type            text        NOT NULL,
    data            jsonb       NOT NULL,
    metadata        jsonb,                    -- кто, откуда, correlation id
    created_at      timestamptz NOT NULL DEFAULT now(),
    UNIQUE (stream_id, version)               -- конкурентная запись с той же версией отклоняется
);

await using var session = store.LightweightSession();
var account = await session.Events.AggregateStreamAsync<Account>(accountId, token: ct);
account!.Withdraw(300_000);
session.Events.Append(accountId, account.Version, account.UncommittedEvents.ToArray());   // проверка версии
await session.SaveChangesAsync(ct);