Resolve AI raises $125M Series A at $1B valuation   Series A extension: $40M at $1.5B - DST Global & Salesforce Ventures   Spiros Xanthos: OpenTelemetry co-creator, 3x founder   Customers: Coinbase, DoorDash, Salesforce, MSCI, Zscaler   70% of engineer time spent maintaining software - Resolve AI is the fix   $160M total funding | 110 employees | San Francisco   Greylock, Lightspeed, Fei-Fei Li, Jeff Dean all in   Resolve AI raises $125M Series A at $1B valuation   Series A extension: $40M at $1.5B - DST Global & Salesforce Ventures   Spiros Xanthos: OpenTelemetry co-creator, 3x founder   Customers: Coinbase, DoorDash, Salesforce, MSCI, Zscaler   70% of engineer time spent maintaining software - Resolve AI is the fix   $160M total funding | 110 employees | San Francisco   Greylock, Lightspeed, Fei-Fei Li, Jeff Dean all in  
Spiros Xanthos, Founder and CEO of Resolve AI
YesPress Profile • Founder

SpirosXanthos

Founder & CEO — Resolve AI

Two exits. One standard that runs the cloud. Now building the AI that keeps it running.

$1.5B Valuation
$160M Total Raised
3x Founder
18mo To Unicorn
$160M Total Funding Raised In under 18 months
110 Employees San Francisco, CA
20yr Co-founder Relationship Met at UIUC grad school

From Stealth to $1.5 Billion in 18 Months

Seed
$35M
Series A
$125M
A Ext.
$40M

Total raised: $160M+ across three rounds, 2024-2026

Lightspeed
Greylock
DST Global
Salesforce Ventures
Unusual Ventures
Artisanal Ventures
A* (Founders Fund)
Notable Angels

Fei-Fei Li (World Labs founder) and Jeff Dean (Google DeepMind) both participated in the seed round - a signal about who in AI is paying attention.

Within 13 months of exiting stealth, Resolve AI landed some of the most demanding engineering organizations in the world:

Coinbase
DoorDash
Salesforce
MSCI
Zscaler
The Problem in Numbers
70%
Engineer time on maintenance
100x
Daily deploys that break runbooks

The Long Game: From Thessaloniki to Unicorn

Xanthos grew up in Thessaloniki, the second-largest city in Greece and, by his account, one of the most beautiful places on earth. He left for the United States in 2004 to pursue a PhD in computer science at the University of Illinois Urbana-Champaign. He never finished it - in the sense that matters for the transcript. He finished it the other way.

Log Insight was the first company: data mining tools for software code analysis. VMware acquired it in 2012. The details of the exit were never public, but the outcome was clear - Xanthos had proven his instinct for building things that enterprises actually need. He spent a brief detour as a marketplace founder (Pattern Insight / EasyHome, home services, 2013-2018), which remains his one non-observability chapter.

Then came Omnition in 2018. The timing was precise. Cloud-native applications were proliferating. Distributed systems meant your one request might touch forty services before returning. Nobody could see inside any of it. Omnition pioneered no-sample distributed tracing - capturing every transaction rather than sampling a subset - and got acquired by Splunk in 2019 before most of the industry had understood the problem they were solving.

At Splunk, Xanthos didn't drift into corporate inertia. He ran the observability business: 400+ engineers, hundreds of millions in ARR, and a front-row seat to the limits of existing tooling at enterprise scale. It's where the thesis for Resolve AI formed - watching brilliant engineers still spending entire weekends diagnosing incidents that should have been caught and resolved automatically.

2004
Moves from Thessaloniki to UIUC for graduate studies. Meets future co-founder Mayank Agarwal.
2006
Drops out of PhD to found Log Insight - data mining for software analysis.
2012
Exit #1: Log Insight acquired by VMware.
2013
Founds Pattern Insight (EasyHome), a home services marketplace. A rare detour outside DevOps.
2018
Founds Omnition, pioneering no-sample distributed tracing for cloud-native apps.
2019
Exit #2: Omnition acquired by Splunk. Xanthos joins as SVP, GM of Observability.
2019
Co-creates OpenTelemetry, which becomes the CNCF standard for cloud-native telemetry.
2024
Leaves Splunk. Co-founds Resolve AI with Agarwal. Seed round: $35M from Greylock, Fei-Fei Li, Jeff Dean.
2026-02
Series A: $125M at $1B valuation. Lightspeed + Greylock lead.
2026-04
Series A Extension: $40M at $1.5B valuation. DST Global + Salesforce Ventures.

The Standard That Runs the Cloud

Before Resolve AI, before Splunk, before the unicorn - Xanthos co-created OpenTelemetry, the open-source observability framework now under the CNCF and used by effectively every major cloud-native company on earth. If your software is running somewhere and someone is watching it, there's a good chance OpenTelemetry is how they're watching.

"Modern software systems are very dynamic and they change very, very frequently, sometimes 10-100 times a day. So, runbooks become obsolete very, very quickly."

- Stack Overflow Blog, 2025

"I don't think this is a problem where we just let the agents run wild from the beginning."

- VentureBeat, 2026

"The next three years will see a massive shift toward AI agents that not only identify problems but solve them independently."

- Silicon Valley Investclub, 2026

Greek Soul, Silicon Valley Speed

Xanthos has been in the United States for more than 20 years and still visits Thessaloniki every summer. He's described Greece as "possibly the most beautiful country on the planet to live in" and his closest friends are still the ones he left behind. This isn't nostalgia - it's a man who made a deliberate bet on where to build, without pretending he didn't leave something behind to do it.

His immigrant's perspective on opportunity is unusually honest: "I really thought I'd return to Greece after just a few years. But in the US, I have been granted ample opportunities to grow, build, and try new things. I don't think there is any other place in the world where an immigrant could have such opportunities." He mentors Greek startup founders through Endeavor Greece, returning capital - in the knowledge sense - to the place that made him.

His co-founding partnership with Mayank Agarwal spans 20 years and three distinct phases: classmates, colleagues, and now co-founders at their most ambitious company yet. The startup world cycles through "founder fit" frameworks constantly; Xanthos and Agarwal simply kept working together long after everyone forgot they'd met in grad school.

Outside the stack, he shoots photos - not metaphorically. Xanthos has a published photography profile on Unsplash, with 12 images available for download. The habit of observation that makes a good systems engineer apparently works at other focal lengths too.

  • Co-created OpenTelemetry - now the CNCF industry standard for cloud-native telemetry collection
  • Sold Log Insight to VMware (2012) - first enterprise exit
  • Sold Omnition to Splunk (2019) - pioneered no-sample distributed tracing
  • Built and ran Splunk's observability business: 400+ engineers, $400M+ ARR
  • Founded Resolve AI; reached $1B valuation in Series A within 13 months of stealth
  • Reached $1.5B valuation with Series A extension - one of the fastest to unicorn in the 2024-26 wave
  • Secured Coinbase, DoorDash, and Salesforce as early enterprise customers
  • Recognized as distinguished alumni by Siebel School of Computing and Data Science, UIUC
  • Backed by Fei-Fei Li and Jeff Dean in the seed round

Details Worth Knowing

01
PhD Dropout to Standard Setter

Xanthos left his PhD at UIUC to start a company. The irony: the work he did after the dropout - co-creating OpenTelemetry - became more cited in the industry than most completed dissertations.

02
The Photographer

Among the code commits and board meetings, Xanthos maintains an active Unsplash photography profile under @spxanthos. 12 published photos. The observability engineer who also watches light.

03
20-Year Co-founder

He met Mayank Agarwal in graduate school in 2004. They've now built multiple companies together across two decades - longer than most startups last, let alone partnerships.

04
The Fei-Fei Li Signal

AI legend Fei-Fei Li and Google DeepMind's Jeff Dean both participated in the Resolve AI seed round. When the people who built the infrastructure of modern AI back your company early, that's a specific kind of validation.

05
Home Services Detour

Between Omnition and Log Insight, Xanthos spent 2.5 years building a home services marketplace. Every founder has the chapter they don't lead with. His lasted 2.5 years and he came back to infrastructure with more conviction than ever.

06
The Name

"Resolve AI" is not accidental. Resolve incidents. Resolve ambiguity. Resolve the on-call nightmare. Three meanings, one brand, zero wasted syllables. Classic engineer-founder naming logic.

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