[3][5] At the young age of 15, he was promoted to Erakor Golden Star first-team, after most of the club's senior players left following their recent relegation to the First Division.

Alongside a promising group of fellow youngsters, they worked hard and won the competition, earning promotion back to the Premier League within two years.

Impressed by Brian's abilities, Colin arranged a six-month scholarship for him to train with the A-League club Wellington Phoenix while continuing to play local football with Waterside Karori.

[17] Despite this, Kaltak was lauded for his standout performances, particularly during the month of December as a key figure in the Mariners' defence;[18] he played a crucial role in helping the team secure a clean sheet in a 3–0 victory against the Newcastle Jets in the F3 Derby[19] and a 2–1 win in the previous match against Sydney FC.

[20] On 11 January 2023, Central Coast Mariners announced that Kaltak would remain with the club until the end of the 2024/2025 season after his side conceded just three goals in the previous five games.

[21] On 4 February, in his second match against Sydney FC, he received a straight red card in the 25th minute for denying Max Burgess an obvious goal-scoring opportunity.

[25] Kaltak remained a key player for the Mariners as his contributions were vital in the team's success, as they secured three consecutive wins against Adelaide United in the final league match (4–1)[26] and both legs of the A-League semi-final (4–1 on aggregate).

[27][28] Kaltak played a significant role in the Mariners' stunning 6–1 victory over Melbourne City in the Grand Final at CommBank Stadium, leading them to lift the A-League Men championship trophy.

[34] Vanuatu's first match was scheduled against Tahiti on 17 March 2022, but the team was forced to withdraw from the tournament without playing a game due to a COVID-19 outbreak among the travelling contingent.

[40] Kaltak, representing Vanuatu, starred alongside Thiago Silva (Brazil), Luka Modrić (Croatia), Pierre-Emerick Aubameyang (Gabon), Andre Blake (Jamaica) and Hassan Maatouk (Lebanon).