I designed, developed and implemented training programs for both the sales, and the technical support teams. The program was successful and is still used to train new staff today. Hi Barak! Your sentence was actually fine, but maybe a little wordy. In my writing I try to limit my sentences to a couple of clauses. If they are longer, with a lot of information, they become difficult to read. When writing a CV or cover letter it is good to give examples of your successes. I invented some information to add to your sentence as an example. I hope this helps! :)

I built and designed training programs from scratch for the customer’s sales and technical support teams, and I was responsible for implementing them successfully.

I was responsible for design and (successful) implementation of the training programs for customer's sales and technical support teams.