Sam Costello

Chief Revenue Officer Harness

Last Reviewed: September 19, 2026

Executive Summary

Sam Costello is Chief Revenue Officer of Harness, the San Francisco company building an AI-driven software delivery platform. He is an internal appointment in the fullest sense: he joined in 2019 when Harness was a Series A company and rose through successive senior sales leadership roles as it grew to more than 1,200 employees, over 1,000 enterprise customers and $570M raised. That trajectory is the unusual part. Enterprise software companies typically import a chief revenue officer from outside once they reach scale, on the theory that selling to the Fortune 500 is a different job from selling to early adopters; Harness instead promoted someone who had done both inside the same company.

Career Highlights

• Chief Revenue Officer of Harness, leading global revenue strategy, sales and go-to-market for its AI software delivery platform.
• Joined Harness in 2019 at Series A and progressed through a series of senior sales leadership roles as the company scaled.
• Held sales leadership positions at Perfecto, helping scale revenue ahead of its sale to Clearlake Capital-backed Perforce Software, a roughly $200M transaction completed in December 2018.
• Led transformational projects inside Fortune 500 customers at Oracle.
• Holds a finance degree from The Ohio State University’s Max M. Fisher College of Business.

Professional Journey

Costello studied finance at The Ohio State University’s Max M. Fisher College of Business and began his career in enterprise software sales at Oracle, where he led transformational projects inside Fortune 500 customers — the kind of long-cycle, multi-stakeholder selling that defines enterprise infrastructure rather than departmental software.

He then moved to Perfecto, the mobile and web application testing company, in sales leadership. His time there ended in an outcome that is a useful credential in its own right: Perfecto was acquired by Perforce Software, backed by Clearlake Capital, in a transaction announced in October 2018 and completed that December for approximately $200 million. Harness describes his contribution as helping scale revenue ahead of that sale, which places him on the growth side of a company being readied for a transaction rather than on the integration side afterwards.

He joined Harness in 2019, when it was a Series A company. Harness had been founded two years earlier in San Francisco by Jyoti Bansal, who had previously built AppDynamics into a business Cisco acquired for $3.7 billion, and Rishi Singh; it was spun out of the BIG Labs startup studio. The proposition was continuous delivery — automating the machinery that moves code from a developer’s branch into production — and it has since widened into testing, security, cloud cost management and, more recently, an argument the company puts plainly: AI writes the code, and Harness ships it.

Costello progressed through a series of senior sales leadership roles across that period, and the company now names him Chief Revenue Officer, responsible for global revenue strategy, sales and go-to-market. The scale he sells into has changed substantially over those years — Harness reports more than 1,000 enterprise customers, 1,200-plus employees and $570 million raised from investors including Goldman Sachs Alternatives, Google Ventures and Battery Ventures. He works alongside a President, Go To Market, so revenue leadership at Harness is structured across two senior roles rather than concentrated in one.

He lives in Redding, California.

Education

The Ohio State University, Max M. Fisher College of Business

Finance