Thin-film solar technology company Midsummer appointed Peter Karaszi public relations and investor relations manager. Karaszi previously served on the board of Prime Weber Shandwick, where he also served as a senior consultant. Midsummer also appointed John Mathisen as sales manager. Mathisen has served in similar roles with companies involved in the sales of windows, roofs, and houses, as well as installations and roof renovations. He joins four new members of the Midsummer sales department: Anneli Nyman, Yin Qiang, Martin Kokko, and Christer Olsson.