In January 2017, Izzuddin and his partner
Goh Sze Fei entered their first Grand Prix Gold final at the
2017 Malaysia Masters and finished up as runner-ups.
2022 In March, Izzuddin and Goh won their first BWF World Tour title at the
2022 German Open beating
Liu Yuchen and
Ou Xuanyi in three games. In the following week, they entered their second consecutive final at the
2022 Swiss Open but lost out to rivals
Fajar Alfian and
Muhammad Rian Ardianto. In April, Izzuddin and Goh fell to compatriots
Aaron Chia and
Soh Wooi Yik at the semi-finals of
2022 Badminton Asia Championships, securing them a bronze medal. In December, Izzuddin captured the
Malaysia International title partnered with
Muhammad Haikal.
2023 In January, following their underwhelming results in the past few months, Izzuddin and long-time partner Goh Sze Fei decided to split-up, citing lack of connection and loss of trust. In March, Izzuddin and new partner Muhammad Haikal reached their first BWF World Tour final at the
2023 Ruichang China Masters, but went down to the home pair of
Chen Boyang and
Liu Yi in rubber game. Around four months after splitting up, Izzuddin and Goh Sze Fei reunited at the end of May. The pair set aside their differences and decided to rekindle their partnership in quest for the
2024 Summer Olympics spot. In July, Izzuddin and Goh competed at the
2023 U.S. Open, their first tournament after reuniting. The pair emerged as winners defeating Chinese Taipei's
Lee Fang-chih and
Lee Fang-jen in the final. The duo also won the Super 100 event in the
Kaohsiung and
Abu Dhabi Masters.
2024 Izzuddin started the 2024 season with unsatisfactory results, as he and Goh suffered multiple early rounds defeats in the Asian and European leg. Izzuddin and Goh finally reached the final of the
Asian Championships in April, winning the silver medal. Their performance started to improve as evidenced by the results they achieved by reaching the quarter-finals of the
Malaysia Masters,
Singapore Open, and
Indonesia Open. In August, it was reported that the pair had decided to leave the
national team, and would officially start their career as independent players in early September. The duo then won the
Japan Open in August,
China Open in September, and
Arctic Open in October. In December, Izzuddin and Goh finished their 2024 season as the runners-up of the
BWF World Tour Finals, losing to Kim Astrup and Anders Skaarup Rasmussen of Denmark in the final with a score of 17–21, 21–17, 11–21. Their achievement elevated them to world number 3, the highest ever ranking in their career. With that, they have become the top Malaysian men's doubles pair, taking over Olympic bronze medalists
Aaron Chia and
Soh Wooi Yik. That achievement also marks them being the first men's doubles pair in Malaysia to reach the final of the BWF World Tour since its establishment in 2018.
2025 Started the season as world number 2 in the BWF ranking, Izzuddin and Goh snapped their first
India Open title by defeating Korean pair of
Kim Won-ho and
Seo Seung-jae in 3 sets. It was also the first title of the year for the pair. In July, Izzuddin and Goh failed to defend their
Japan Open crown the previous year, losing to Kim and Seo in straight sets.
2026 In January, Izzuddin and Goh won their first title in the
Indonesia Masters against
Raymond Indra and
Nikolaus Joaquin of Indonesia. == Achievements ==