Meet Our Legal Experts – Lexonix & Co

Team and career

Our team consists of highly qualified professionals specializing in various areas of legal practice.

We are driven by unyielding enthusiasm, inspiration and a special attitude to everything we do.

Yacob Harimilu Siregar

MANAGING PARTNER

With a background at OPPO Indonesia, Yacob has built a strong track record in corporate law, compliance, and high-impact litigation.

e: yacobhs@lexonixnco.com

tel: +(62) 878-7167-9799

Renaldi Sidabutar

MANAGING PARTNER

Renaldi’s legal career spans roles at Warison Simarmata Law Office and Sands Group Indonesia, focusing on corporate, administrative, and competition law.

e: renaldisidabutar@lexonixnco.com

tel: +(62) 812-6513-0420

Ganiviantara Pratama

MANAGING PARTNER

Ganiviantara has handled complex legal matters in corporate, criminal, and cyber law through his experience at Hummerson Law Firm and OPPO Indonesia.

e: ganiviantara@lexonixnco.com

tel: +(62) 857-7532-7786

Lexonix & Co
Ready to assist.

You can access the Lexonix & Co Company Profile to gain a comprehensive understanding of our firm, including our legal expertise, core values, and key practice areas.

Lexonix & Co – Company Profile 2025

TALK TO US

+62 8577 5327 786

WHERE WE ARE

Inifiti Office, Bellezza BSA 1st Floor Unit 106, Kebayoran Lama, Jakarta Selatan 122210

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"The greatest glory in living lies not in never falling, but in rising every time we fall." - Nelson Mandela

© 2025 Lexonix & Co. All Right Reserve

Yacob Harimilu Siregar

Yacob Harimilu Siregar stands as a beacon of legal acumen and leadership in Indonesia’s dynamic legal landscape, serving as the visionary Managing Partner of Lexonix & Co., a premier law firm renowned for its innovative approach to corporate legal services. A distinguished alumnus of Sekolah Tinggi Hukum Bandung, Yacob’s academic foundation laid the groundwork for a career marked by intellectual rigor, strategic foresight, and an unwavering commitment to client success.
With a career spanning diverse and high-stakes legal environments, Yacob has cultivated a reputation as a trusted advisor and formidable advocate. As Inhouse Counsel at OPPO Indonesia, Yacob played a pivotal role in steering the multinational corporation through Indonesia’s regulatory landscape. From drafting ironclad contracts to spearheading compliance initiatives and supporting high-value corporate transactions, he demonstrated an exceptional ability to balance legal precision with commercial pragmatism.

Renaldi Sidabutar

Renaldi Sidabutar is a seasoned legal professional and the Managing Partner of Lexonix & Co. A graduate of Universitas Sumatera Utara, Renaldi brings extensive expertise and a proven track record in various legal domains. His professional experience includes serving as a Junior Lawyer at Warison Simarmata Law Office and as Inhouse Counsel at Sands Group Indonesia, where he honed his skills in navigating complex legal challenges.
Renaldi specializes in corporate law, corporate compliance, corporate litigation, mergers and acquisitions, criminal litigation, labor litigation, administrative litigation, and competition law. His comprehensive knowledge and strategic approach enable him to provide exceptional legal counsel to clients across diverse industries.
As a licensed advocate with the Indonesian Advocates Association (Perhimpunan Advokat Indonesia), Renaldi is committed to delivering high-quality legal services, ensuring compliance, and driving successful outcomes for Lexonix & Co. and its clients.

Ganiviantara Pratama

Ganiviantara Pratama is an accomplished legal professional and a Partner at Lexonix & Co. A graduate of Universitas Lampung, Ganiviantara brings a wealth of experience and specialized expertise to the firm. His professional journey includes serving as a Corporate Lawyer at Hummerson Law Firm and as Inhouse Counsel at OPPO Indonesia, where he developed a strong foundation in addressing complex legal matters. Ganiviantara specializes in corporate law, corporate compliance, corporate litigation, mergers and acquisitions, criminal litigation, labor litigation, administrative litigation, competition law, constitutional litigation, data protection law, and cyber law. His broad expertise and strategic insight enable him to deliver comprehensive legal solutions tailored to the needs of clients across various sectors.
Holding a license as an advocate from the Indonesian Advocates Association (Perhimpunan Advokat Indonesia), Ganiviantara is dedicated to upholding the highest standards of legal practice, ensuring compliance, and driving successful outcomes for Lexonix & Co. and its clients. He is committed to serving clients’ interests with professionalism and high integrity.