Skyscraper-sized billboards show assault troops in battle gear emerging from a ball of flames. On street posters, soldiers urge passers-by to enlist, proclaiming that “victory is in your hands.” Take a seat on a high-speed train and chances are high that a television will be advertising jobs for drone operators.

Slick recruiting campaigns brimming with nationalist fervor have become ubiquitous in Kyiv, the capital, and other Ukrainian cities in recent months. They are perhaps the most visible sign of a push to replenish Ukrainian troops depleted by more than two years of a brutal war — an effort that experts and officials say is crucial for fending off relentless Russian attacks.

But most of the campaigns are not the work of the country’s political and military leadership. They are the initiatives of troop-starved brigades that have taken matters into their own hands, shunning an official mobilization system that they say is dysfunctional, often drafting people who are unfit and unwilling to fight.

“These campaigns are much more effective because we’re getting exactly the people we need,” said Dmytro Koziatynskyi, a combat medic turned recruiter in the Da Vinci Wolves battalion, which started as a paramilitary wing of a coalition of far-right political parties after Russia’s 2014 annexation of Crimea.

The battalion, which has now been absorbed into Ukraine’s armed forces, is currently seeking about 500 new members and has advertised jobs as varied as medics, mechanics and sappers, combat engineers who clear minefields. Recruiters conduct lengthy interviews, trying to find positions that match candidates’ skills. People can opt out after a few days of training if they do not like it.