Jan Pietrzak

69.20.Z - Accounting, bookkeeping and auditing activities; tax consultancy

62.01.Z - Computer programming activities

62.09.Z - Other information technology and computer service activities

63.11.Z - Data processing, hosting and related activities

63.12.Z - Web portals

74.90.Z - Other professional, scientific and technical activities not elsewhere classified

82.11.Z - Office administrative service activities

85.59.B - Other out-of-school forms of education, not elsewhere classified

95.11.Z - Repair and maintenance of computers and peripheral equipment