Tafer was born in the city of Grenoble in the Rhône-Alpes region to an Algerian father, who emigrated to France from Constantine, and a Portuguese mother.

After spending seven years with his childhood club, Tafer signed an aspirant (youth) contract with the then three-time champions Olympique Lyonnais.

[5][6][7] On 24 January 2009, Tafer made his professional debut in the club's Coupe de France match against Concarneau coming on as a substitute in the 75th minute.

[8] Two weeks later, Tafer made his league debut making a one-minute cameo appearance in a 3–1 victory over Nice.

On 26 September 2009 in his season debut, he scored his first professional goal against Toulouse after appearing in the match as a halftime substitute.

[11] On 13 January 2010, Tafer made his first career start in a 3–0 win over Metz in the Coupe de la Ligue playing the entire match.

[17] Xamax confirmed on 4 January 2020, that Tafer had signed a deal until the end of the season with the club, with an option for one further year.

[22] In the Elite Round portion of qualification for the 2008 UEFA European Under-17 Football Championship, Tafer scored a double against Israel in the team's second group stage match.

The match was played at Wembley Stadium in front of 15,000 spectators and the victory resulted in the team being presented the Fallenhero Trophy by The Football Association chairman Trevor Brooking.

[28][29] For under-19 duty, Tafer was again called upon by coach Francis Smerecki making his first appearance with the team at the 2009 edition of the Sendaï Cup.

[30] In the final, Tafer appeared as a halftime substitute and assisted on the team's opening goal scored by Gilles Sunu.

Due to France's victory at the UEFA Under-19 championship, the nation qualified for the 2011 FIFA U-20 World Cup, which merited under-20 team appearances for Tafer.

Tafer later participated in the 2011 Toulon Tournament with the under-20 team and scored a goal in a 4–1 group stage win over Mexico.