Working at GreatHorn | Glassdoor

GreatHorn Overview

Belmont, MA
1 to 50 employees
Company - Private
Enterprise Software & Network Solutions
Unknown / Non-Applicable
GreatHorn is the world's first truly next generation email security company.

We protecting cloud native email platforms from today's cyberthreats ... Read more

Mission: We enable our clients to securely embrace collaborative cloud technology by protecting the data, intellectual property, and financial resources of their people.

Company Updates

  • We're excited to be presenting at SecureWorld Boston today! Come say hello at booth #356, or listen to our CEO Kevin O'Brien present at 1:15pm in room #103 on Phishing and Social Engineering! (We're actively hiring for multiple roles in Engineering, Sales, and Marketing!)

  • Sales, Marketing, and Engineering gathered together to kick off Q3 FY17, overlooking Charles River and the Boston Skyline!

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GreatHorn – Why Work For Us?

Enabling Cloud Communication At Scale

Targeted cyberattacks are the fastest growing threat to today's company's, encompassing a complex set of tactics, techniques, and procedures that criminal hackers use to breach security defenses and steal financial resources, sensitive IP, and personal data.

The impact of these attacks is tremendous (>$400m in damages as of the most recent FBI studies), and legacy vendors -- focused on on-premise technology and point solutions for email -- have failed to keep up.

GreatHorn is next generation, cloud-native email security platform, combining machine learning-driven threat detection and automated response capabilities to enable our customers to identify and shut down these types of attacks before damage occurs. 

Who We Are

We're a team of serial entrepreneurs and cybersecurity veterans, solving a massive problem in an enormous market, and we're committed to the success of our customers and colleagues. 

Our diverse backgrounds and collaborative, creative, passionate approach to problem solving means that rally around a culture that values teamwork, attention to detail, hard work, and innovation. Our core values are simple:

Rule 0: No a**holes.
Rule 1: Ask questions.
Rule 2: Details matter.
Rule 3: Experiment, then iterate. 
Rule 4: Be a team.
Rule 5: Power through.

What We Believe

We believe that security is a competitive advantage for today's enterprises, and that digital transformation and cloud-enabled communication rely on trust. GreatHorn enables organizations to embrace those technologies while protecting their clients' data, financial resources, and intellectual property from advanced targeted threats.

Integrity, collaboration, honesty, and follow-through are fundamental to who we are, and our commitment to uphold our values underscores everything we do. 

We believe strongly in diversity, and seek to recognize, develop and support talent from all backgrounds.

undefinedKevin O’Brien

CEO and Co-Founder

Kevin has 16 years of experience in the technology sector. He has served in various sales, marketing, and operational roles throughout his career, helping companies from pre-revenue to product-market-fit and rapid growth. GreatHorn is the 6th early stage company of which he has been a part. Kevin is a regular author and speaker on security and its role in the digital economy and holds a BA in philosophy from the University of Massachusetts Amherst.


undefinedRay Wallace

CTO and Co-Founder

Ray is a highly accomplished full-stack engineer and architect and has been developing high-functioning teams in the Boston startup world since the early 2000s. With significant experience in application and database security, front and back-end infrastructure and analytics, Ray is responsible for GreatHorn’s technical direction and vision – overseeing product design, implementation, and roadmap.

Ray’s background is in compiler design, semantic analysis, and managing high-volume data problems through specialized language creation and implementation; he studied both Computer Science and Mathematics at RIT.


GreatHorn’s biggest, most disruptive strength: Our team.

We’re building a new cloud security platform that gives security teams the visibility and control they need to stop email attacks, and we’re looking for talented, passionate, positive, incredibly smart people to join us.

With multiple customers in production, a data set encompassing hundreds of thousands of emails and authentication events, and simple deployment options for popular systems such as Google Apps and AWS, we’re growing incredibly quickly and redefining early stage security.

We are a highly experienced team with multiple successful startups under our belts and a data-driven approach to defining and solving problems. We’re serious about fostering a “no a**hole” culture.

We offer competitive salaries, equity options, health, vision, and dental insurance, and a matched 401k. Our offices are within walking distance of the Belmont Center MBTA stop, with plenty of on-street parking and easy access to multiple public transportation options.

GreatHorn Reviews

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Kevin O'Brien
11 Ratings
  • "Riding the Wave"

    • Work/Life Balance
    • Culture & Values
    • Career Opportunities
    • Comp & Benefits
    • Senior Management
    Current Employee - Inside Sales in Belmont, MA
    Current Employee - Inside Sales in Belmont, MA
    Positive Outlook
    Approves of CEO

    I have been working at GreatHorn full-time (Less than a year)


    I have worked for a few start ups, and GreatHorn has been a great experience thus far. The tech is on the right side of what seems to be a wave of change. The leadership is devoted and the general vibe is pleasant. This requires work and long hours, but the payoff is there.


    This is not a 9-5, it requires extra work and every team member must be adaptable and willing to wear multiple hats.

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GreatHorn Photos

GreatHorn photo of: On stage at Techstars Demo Day, 2015
GreatHorn photo of: GreatHorn Sales Team at Work!
GreatHorn photo of: 2017 Team Offsite
GreatHorn photo of: 2017 Team Offsite
GreatHorn photo of: Kicking off the year in a restored 1809 farmhouse
GreatHorn photo of: Pre-sales kickoff hike
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GreatHorn Interviews



Getting an Interview

Getting an Interview





    QA Lead Interview

    Anonymous Employee in Belmont, MA
    Accepted Offer
    Positive Experience
    Easy Interview


    I applied online. The process took 1 day. I interviewed at GreatHorn (Belmont, MA) in December 2017.


    The hiring manager contacted me and set up a phone screen. I spoke with the lead software engineer. We discussed the role and how it would support the team's mission. The phone screen was focused and the discussion concentrated on the role of Software QA in a startup environment and small teams. For the onsite, I met the Lead Software Engineer, DevOps, Product management and the CTO. The team is high performing and a big factor is how you'll interact with the team and if you're a fit for the company. Overall the experience was great, especially compared to the bloated process you find with larger companies. The phone screen was set up shortly after I applied and I had an offer from the CTO a few hours after my onsite interview concluded. The entire process was professional and the interviewers friendly and courteous.

    Interview Questions

    • Describe how you used Selenium Grid for testing.   1 Answer
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GreatHorn Awards & Accolades

  • Tech Trailblazers Award: Cloud, Tech Trailblazers, 2016
  • 2017 CRN Security 100: 20 Coolest Security Vendors, CRN Security 100, 2017
  • Innovative Tech of the Year - Security (Finalist), Massachusetts Technology Leadership Council (MassTLC), 2017
  • RSA Innovation Sandbox, RSA Conference, 2017
  • 10 Email Security Startups To Watch In 2017, CBInsights, 2017
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