At embassies, NGOs (http://wango.org/resource...), some hotels. A few hundred expatriates live in Dushanbe. Several ads each week in the electronic newsletter WhatsOnInDushanbe. For investors, cf. (http://doingbusiness.org/...) and similar publications.
Habitat for Humanity-Tajikistan, (http://habitat.tj/), constructs homes for needy, low-income families in addition to completing many unfinished Soviet-era homes and apartment blocks, provides seismic retrofits, works to provide sanitary water, and more. Once or twice a year, volunteer trips through HFH "Global Village" program, (http://habitat.org/cd/gv/schedule.aspx ) are offered, entailing 2 weeks of building houses combined with a few days of sightseeing.
Tajikistan is a stunning place, and there is plenty to do, from the Silk Road mystique of places like Khujand and Istaravshan, to the stunning, untouched mountain scenery of the Pamirs and their accompanying allure of unclimbed peaks and virgin trekking routes. Fan Mountains could be a good alternative to the Pamirs. They are easy to reach and provide good trekking options.