[5] He then won the boys' doubles title with Leo Rolly Carnando at the Astec Open Championships in Jakarta,[6] and later at the Singapore Youth International Series.

[19] In May, he and Carnando won the Jaya Raya Junior Grand Prix beating number 1 seed Di Zijian and Wang Chang.

[20] The duo also won the Malaysia International Series,[21] and managed to secure the gold medal at the Asian and World Junior Championships.

[27][28] They then reached the finals of the Hylo Open, but was defeated by World number 1 Marcus Fernaldi Gideon and Kevin Sanjaya Sukamuljo in straight game.

[33][34] In July, Marthin and Carnando clinched their first World Tour title at the Singapore Open by beating Fajar Alfian and Muhammad Rian Ardianto in the final.

[42][43] At the Orléans Masters in France, they reached the semi-finals losing to fellow Indonesian pair Muhammad Shohibul Fikri and Bagas Maulana.

[44] Marthin made his debut at the Asian Championships in Dubai, United Arab Emirates, but he and his partner, Carnando, had to lose in the first round from 2nd seed Malaysian pair Aaron Chia and Soh Wooi Yik.

[55] Marthin made his debut at the Asian Games in Hangzhou,[56] but unable to win any medals in both the men's doubles and team events.

[63][64] In 2025, Daniel continuing his partnership with Fikri and manage to finish as a runner-up to Seo Seung-jae and Jin Yong from Korea in Thailand Masters.