In 1985, Wallach, along with Saul Steinberg and Henry Silverman of Reliance Capital Group L. P., founded Telemundo,[1][2] which is today the second-largest Spanish-language television network in the United States.

[3] Wallach attended Boston University for post graduate studies in business after receiving a BBA from the City College of New York.

[2] Under Wallach's guidance, by 1980, TV Globo grew to dominate the Brazilian market and became the 4th largest network in the world, with 31 affiliates and programming provided to 80 countries.

[1][2][9][10] After leaving Telemundo in 1987, Wallach was a consultant for the Italian network, Tele Monte Carlo owned by TV Globo.

[11] As president of GloboSat he launched and operated the first pay television, 4-channel DBS broadcast system covering Brazil.