Tim Sadler
CEO and Co-Founder



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Tim Sadler began his professional career over 12 years ago. Today, he is the Co-Founder and CEO of Tessian. Tessian automatically stops data breaches and security threats caused by human error – like data exfiltration, accidental data loss, business email compromise and phishing attacks – with minimal disruption to employees’ workflow.

Sadler first got his start in 2009 as a research & development engineer at GE. From there, he went on to Trac Group Limited, before eventually rising to global banking analyst at HSBC Global Banking & Markets, his most recent position prior to joining Tessian.

Sadler graduated from Imperial College of London with a master’s degree in mechanical engineering.



  1. Visionary leader: Tim identified that there was a gap in the cybersecurity market and has created and defined a new category of cybersecurity software called Human Layer Security to fill that gap. He continually reminds the company of the mission and inspires every team (and investors) with his vision. Grit and perseverance: Since starting the company in 2013, Tim has grown the company to over 150 employees in the UK and US, raised over $120m in funding from legendary investors like Sequoia and Accel and built a multi-award winning company, valued at $500m in 2021. Not only was 2020 a tough year for all leaders, Tim had added stress having relocated from the UK to the US just a month before the pandemic sent us all into lockdown. Yet, he continued to successfully lead the company, retain talent and secure a Series C funding round. Human first: Tim is an empathetic and compassionate leader, and put employees’ wellbeing first. Before and during the pandemic, Tim and other senior leaders have rolled out a number of initiatives to give Tessian employees time off to focus on their mental health and made access to therapists and help readily available for all members of staff.

    Mid-Level Professional, submitted on

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