Dances on the Snow by Sergey Lukyanenko; your description is accurate.
Tikkirey "Tiki" Frost lives on the planet Quarry, poorly adapted for human life and stricken with poverty. Due to the planet's high radioactivity, the inhabitants of Quarry are forced to live in a protective dome and pay for food and air, or "social support". Unemployment is a major problem on Quarry. In fact, one's ability to obtain a job depends on the quality of his or her neuroshunt implant, allowing direct mind-to-machine connection. Tikkirey's parents' neuroshunts have become obsolete and they have no money for an upgrade. His father has been unemployed for years, and his mother makes a pittance. Incapable of paying for their social support, Tikkirey's parents are forced to invoke their "constitutional right to commit suicide." For that, Tikkirey's social support is extended by 7 years, during which he can get education and find a job, as his neuroshunt is above the local standard. If his parents forgo their "constitutional right", the entire family will be evicted from the Dome. The life expectancy outside the Dome is 1–2 years.
After losing his parents, Tikkirey decides to leave Quarry by any means necessary. As such, he signs up on an interstellar ore transport as a "calculation module" — a wetware computer used for complex calculations at faster-than-light speeds, as normal computers fail to work. A calculation module remains in suspended animation, most of the time, while a stream of data is shunted through his brain. While this is a highly paid position, continuous misuse of the brain atrophies the frontal lobe, causing the person to lose his free will. After the expiration of the standard five-year contract, 97% of calculation modules are incapable of making their own decisions and continue flying for the rest of their lives. The other 3% manage to muster enough willpower to leave the ship (2%) or cancel the contract before time is up (1%); however, even they have to spend years relearning to make even the simplest decisions (e.g. a simple choice of soft drink is an extremely difficult process for them).
After regaining consciousness on the beautiful and wealthy planet of New Kuwait, Tikkirey demands to cancel his contract and leave the ship. He immediately finds out that a clause in the contract prevents him from doing just that, as he must pay off his 150,000 credit insurance policy, which will require Tikkirey to serve another 1.5 years on the ship. The contract is specifically written to prevent calculation modules from using ships as free rides. Fortunately, Tikkirey finds out that the crew took pity on the boy and broke the law by not getting him an insurance policy. He receives his earned credits and leaves the ship. He then takes a taxi and gets a room at a cheap hotel. He then hits another snag: his money will only last him about a week. New Kuwait's laws require local permanent residency for employment, but the process of obtaining it takes at least six months....