The core activity of the company "rubí gmbh" encompasses the provision of services in the areas of accounting, personnel administration, and tax returns. Specifically, the company offers the following services: * Accounting: Maintenance of financial accounting, creation of invoices, payment transactions, collection, dunning, creation of interim and annual financial statements * Personnel administration: Maintenance of payroll accounting, creation of payroll declarations for social insurance, creation of withholding tax statements, creation of payroll certificates * Tax returns: Preparation of tax returns, consulting on tax matters The company supports its customers in managing their finances and personnel matters, allowing them to focus on their core business.