S. Sridhar Thewar is the Founder, CEO and Chief Architect of NexusSec, a cybersecurity and IT-infrastructure firm headquartered in Airoli, Navi Mumbai, India. He has over four years of hands-on experience in enterprise network architecture and offensive security, and leads the firm's technical direction across VAPT, next-generation firewall deployment, secure network design and managed security.
- Role
- Founder, CEO & Chief Architect
- Based in
- Navi Mumbai, India
- Experience
- 4+ years
Background
Sridhar founded NexusSec on a single principle: security is not a feature, it is architecture. After four years working hands-on in network architecture and offensive security, he established the firm to close the gap between theoretical compliance and genuinely combat-ready security engineering.
His approach is shaped by offensive experience — designing defences from the perspective of someone who has spent years finding ways through them. That informs how NexusSec scopes engagements: reconnaissance first, architecture second, and validation by testing rather than assumption.
He summarises his philosophy simply: "Architecture is the first line of defense."
Areas of expertise
Network ArchitectureOffensive Security
Penetration TestingVAPT
Next-Generation FirewallsZero Trust Architecture
Network SegmentationSD-WAN
Red TeamingInfrastructure Security
Verified credentials
Sophos Firewall Architect — issued by Sophos and independently verifiable on Credly. The credential covers architecture-level design and deployment of Sophos XGS firewalls, which underpins NexusSec's work as a Sophos Silver Partner.
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What he leads at NexusSec
As Chief Architect he sets technical direction across the firm's service lines — VAPT and red teaming, firewall deployment, network architecture, SD-WAN, server and storage deployment, and managed security. NexusSec is a Sophos Silver Partner, an official Fortinet partner, and a WatchGuard partner.
Published guides
He authors NexusSec's technical guides for Indian businesses:
Frequently asked questions
Who is S. Sridhar Thewar?
S. Sridhar Thewar is the Founder, CEO and Chief Architect of NexusSec, a cybersecurity and IT-infrastructure firm headquartered in Airoli, Navi Mumbai, Maharashtra, India. He has over four years of hands-on experience in enterprise network architecture and offensive security, and leads the company's technical direction across VAPT, firewall deployment, secure network design and managed security.
What company did Sridhar Thewar found?
He founded NexusSec (nexussec.org), a B2B cybersecurity and IT-infrastructure engineering firm based in Navi Mumbai, India. NexusSec is a Sophos Silver Partner, an official Fortinet partner, and a WatchGuard partner, serving businesses across Navi Mumbai, Mumbai and India.
What is Sridhar Thewar's expertise?
His expertise spans enterprise network architecture, offensive security and penetration testing, next-generation firewall deployment, zero-trust architecture, network segmentation and SD-WAN. He founded NexusSec to close the gap between theoretical compliance and combat-ready security engineering.
Where is Sridhar Thewar based?
He is based in Airoli, Navi Mumbai, Maharashtra, India, where NexusSec is headquartered. The firm serves clients across Navi Mumbai, Mumbai and all of India, and works remotely worldwide.
What has Sridhar Thewar written?
He authors NexusSec's technical guides, including 'Top Firewalls to Deploy in 2026', 'Top 10 Cybersecurity Threats in 2026 (India)', 'Top 7 Network Security Mistakes Indian Businesses Make', 'What Is VAPT and Why Your Business Needs It', 'SD-WAN vs MPLS', and 'A Practical Zero-Trust Checklist for Growing Businesses'.
NexusSec.