def serialize_hiring_cost(row) -> dict:
    return {
        "id": str(row.id),
        "job_post_id": str(row.job_post_id) if row.job_post_id else None,
        "source_channel_id": row.source_channel_id,
        "cost_type": row.cost_type,
        "amount": row.amount,
        "currency": row.currency,
        "incurred_at": row.incurred_at.isoformat() if row.incurred_at else None,
        "description": row.description,
        "created_by": str(row.created_by) if row.created_by else None,
        "created_at": row.created_at.isoformat() if row.created_at else None,
        "updated_at": row.updated_at.isoformat() if row.updated_at else None,
    }