# Yun Park

![Yun Park](/resources/cognition/portraits/yun-park.webp)

Cognition MTS (Devin Oncall); ex-TierZero co-founder & CTO; Databricks engineer #25  
Cognition  
San Francisco, California, United States

## At Cognition

- Role: Member of Technical Staff (Engineering)
- Joined: Jun 2024
- How they joined: With TierZero (https://www.autumn.ai/resources/cognition/acquisitions/tierzero)
- Before TierZero: Engineering Leader, Databricks
- Overlapped before Cognition with other Cognition people at: UC Berkeley; Databricks (https://www.autumn.ai/resources/cognition/worked-together)

## Identity
- LinkedIn: https://www.linkedin.com/in/yunpark93
- X: @yunpark93
- GitHub: https://github.com/yunpark93
- Website: https://www.tierzero.ai/blog/authors/yun-park/
- Domain: cognition.ai

## Notes
- Devin Oncall launch post, quoted verbatim: "TierZero joined Cognition with the vision of a single platform autonomously handling your full SDLC. Today, we are taking one step closer towards that vision by launching Devin Oncall, your always-on AI software engineer." The launch shows the TierZero production-agent work shipped inside Devin about three months after the deal. (https://www.linkedin.com/posts/yunpark93_introducing-devin-oncall-devin-automatically-activity-7516560458439557120-7Q4a)
- Joined Cognition as Member of Technical Staff in June 2026, when Cognition acquired TierZero, the company he co-founded with Anhang Zhu in June 2024. (https://www.linkedin.com/in/yunpark93)
- On X he wrote: "Excited to launch Devin Oncall today! Over the past few months, we brought all of our learnings over the past 2 years developing AI agents for production into Devin". (https://x.com/yunpark93/status/2110800222339453129)
- Three-month reflection on Cognition, quoted verbatim: "It's been 3 months since I joined Cognition and it's been such an amazing time working with a super talented "Avengers" team in one of the most excited spaces right now!" He listed the $48B raise led by a16z and Accel, SWE-2, Fusion in Devin CLI and Devin Voice, and ended with a recruiting call. (https://www.linkedin.com/posts/yunpark93_its-been-3-months-since-i-joined-cognition-activity-7505675229700976640-F4Qk)
- Announced the Cognition acquisition on LinkedIn, quoted verbatim: "We're super excited to announce TierZero is joining Cognition! The past two years has been an incredible journey with our team, investors, and customers and it's hard to put into words how grateful I am with all of the trust they all have given us." This dates the TierZero exit to July 2026, about two years after founding. (https://www.linkedin.com/posts/yunpark93_two-years-ago-yun-park-and-i-set-out-to-activity-7485067083907645440-0hit)
- Accel says he left Berkeley in 2015 "to join Databricks as engineer #25", spent the next decade in software infrastructure there, and most recently "led the AI Serving and Ops team". (https://www.accel.com/news/cognition-acquires-tierzero-building-the-autonomous-engineering-agent)
- Cognition's official X account welcomed "@anhangz and @yunpark93 from TierZero to Cognition", and he retweeted it. This confirms co-founder Anhang Zhu joined Cognition with him. (https://x.com/yunpark93/status/2079298639986581580)
- Accel led TierZero's seed round. Accel also backed co-founder Anhang Zhu's earlier company Mayhem in 2018, before Niantic acquired it. (https://www.accel.com/news/cognition-acquires-tierzero-building-the-autonomous-engineering-agent)
- Anhang Zhu's acquisition post: "Two years ago, Yun Park and I set out to make software self-driving." He named customers Brex, Discord, Drata and Speak, and said the idea came from running engineering teams at Facebook, Databricks and Niantic. (https://www.linkedin.com/posts/anhangzhu_two-years-ago-yun-park-and-i-set-out-to-activity-7485064126508212224-90UF)
- TierZero's About page lists him as Co-Founder & CTO and describes his Databricks role as "Engineering lead for Cloud Infra, AI Model Serving, and AI Agent Framework." (https://www.tierzero.ai/about/)
- Before the acquisition, Accel said TierZero served "tens of thousands of engineers" at companies like Brex, Discord and Drata after launching quietly the previous year. (https://www.accel.com/news/cognition-acquires-tierzero-building-the-autonomous-engineering-agent)
- Co-founder and CEO Anhang Zhu was Director of Engineering at Niantic and CTO of Mayhem.gg (acquired by Niantic), where he owned social infrastructure for more than 50M daily players. (https://www.tierzero.ai/about/)
- Described internal TierZero agent-quality work: "agent evals, proxy MCP arch for context management, and adversarial agent teams." (https://www.linkedin.com/posts/yunpark93_you-probably-saw-a-calendar-of-everything-activity-7442947010271506432-PONa)
- Announced TierZero remote MCP support for Claude Code and Cursor. His argument: "Generic MCP servers don't know what telemetry exists, where it lives, how to query it" and lack accumulated team context. This was the core product thesis later folded into Devin. (https://www.linkedin.com/posts/yunpark93_one-thing-our-engineering-team-keeps-running-activity-7416884940027568128-by0y)
- His LinkedIn summary says he "Scaled and led a 40-person engineering organization overseeing all enterprise admin products (identity, billing, cloud security) at Databricks". (https://www.linkedin.com/in/yunpark93)
- A May 2019 Databricks engineering blog post on third-party SSO, written by an intern, thanks "my manager, Yun Park". (https://www.databricks.com/blog/2019/05/03/single-sign-on-sso-to-third-party-applications.html)
- Public headline says "Member of Technical Staff at Cognition". (https://www.linkedin.com/in/yunpark93)
- Said TierZero was at the top of the Cursor marketplace list and pitched it as using "tribal knowledge" (past alerts, incidents and investigation paths) beyond raw MCP-to-telemetry access. (https://www.linkedin.com/posts/yunpark93_look-who-is-top-of-the-list-on-cursor-marketplace-activity-7458608439699656704-nTv2)
- LangSmith for Startups spotlight: "we've integrated TierZero itself to LangSmith as a data source to auto-improve our agents real-time!". (https://www.linkedin.com/posts/yunpark93_langsmith-for-startups-spotlight-tierzero-activity-7432852510153015297-s1NL)
- He wrote TierZero blog posts including 'AI Production Agents: The 2026 Landscape' (2026-02-12), 'Build vs. Buy: Should You Build Your Own AI Production Agent?' (2026-01-27) and 'How to Scale Reliability Without Scaling Headcount' (2026-01-05). (https://www.tierzero.ai/blog/authors/yun-park/)
- Described TierZero's agentic memory: an "agentic search memory layer" plus an LLM-based learning pipeline for quality control, deduplication and staleness detection, with transparent attribution of which memories shaped each response. (https://www.linkedin.com/posts/yunpark93_how-tierzero-uses-agentic-memory-at-tierzero-activity-7401658917711462400-sB7e)
- Described TierZero's agent evaluation pipeline "powered end-to-end by LangSmith (LangChain) and Databricks", using LLM-as-a-judge online monitoring plus trace review to learn from human feedback. (https://www.linkedin.com/posts/yunpark93_evaluating-ai-agents-can-be-trickyespecially-activity-7396947936284307456-rfVx)
- - Building TierZero, an AI platform that helps engineering teams run production systems reliably at scale. Our agents automate incident response, surface reliability risks, and give engineers instant answers to production questions.
- Engineer #25 at Databricks. Tech lead of AI Agent Framework and Model Serving.
- Scaled and led a 40-person engineering organization overseeing all enterprise admin products (identity, billing, cloud security) at Databricks; this comes from the profile summary and preserves the person's own positioning. (https://www.linkedin.com/in/yunpark93)
- TierZero recruiting post: "Developing software has changed completely over the past 6 months. Come join us to redefine how you run your code in production here at TierZero!" It was posted alongside an a16z-team publication. (https://www.linkedin.com/posts/yunpark93_every-week-our-a16z-team-publishes-a-new-activity-7442309756872105984-MEBa)
- Before Databricks he interned in software engineering at Google (Mountain View, summer 2013) and Pinterest (San Francisco, summer 2014). He was also a UC Berkeley Graduate Student Instructor from 2013 to 2015 while studying for his EECS bachelor's (2011-2015). (https://www.linkedin.com/in/yunpark93)
- Previous roles include CTO & Co-Founder at TierZero AI; Engineering Leader at Databricks; Graduate Student Instructor at UC Berkeley; Software Engineering Intern at Pinterest; Software Engineering Intern at Google. (https://www.linkedin.com/in/yunpark93)
- Education history includes Bachelor's Degree, Electrical Engineering and Computer Science, University of California, Berkeley. (https://www.linkedin.com/in/yunpark93)
- His GitHub account (yunpark93, bio "Member of Technical Staff, Cognition AI") has only 5 public repos and 4 followers. (https://github.com/yunpark93)
- In 2021 he posted about Databricks reaching a $38B valuation: "Super amazing to be part of a company that continues to be the leader in the data and AI space". (https://www.linkedin.com/posts/yunpark93_databricks-reaches-38-billion-valuation-activity-6838504826347761664-ZfSO)
- Location is San Francisco, California, United States. (https://www.linkedin.com/in/yunpark93)

## Experience
- Member of Technical Staff at Cognition (Jun 2026 - Present): Cognition builds Devin. Devin plans, writes, tests, and ships production code on its own, working inside your codebase and the tools your team already uses. Devin is deployed at some of the largest and most complex institutions in the world.
- CTO & Co-Founder at TierZero AI - San Francisco, California, United States (Jun 2024 - Jun 2026): Acquired by Cognition. TierZero is an AI platform that helps engineering teams run production systems reliably at scale. Our agents automate incident response, surface reliability risks, and give engineers instant answers to production questions.
- Engineering Leader at Databricks - San Francisco Bay Area (Jun 2015 - Jun 2024): Databricks is the leading Lakehouse Platform. It unifies your data, analytics and AI and enables you to use it to power agents, apps and natural language insights.
- Graduate Student Instructor at UC Berkeley - Berkeley, CA (Jan 2013 - May 2015)
- Software Engineering Intern at Pinterest - San Francisco, CA (Jun 2014 - Aug 2014)
- Software Engineering Intern at Google - Mountain View, CA (May 2013 - Aug 2013)

## Education
- University of California, Berkeley - Bachelor's Degree, Electrical Engineering and Computer Science - (Jan 2011 - Jan 2015)

## Sources
- https://www.linkedin.com/in/yunpark93
- https://www.accel.com/news/cognition-acquires-tierzero-building-the-autonomous-engineering-agent
- https://www.linkedin.com/in/yunpark93?miniProfileUrn=urn%3Ali%3Afsd_profile%3AACoAAAn-whIBZVwhkyI7dAxMb5U6U8zrEu4ivtw
- https://www.tierzero.ai/about/
- https://www.databricks.com/blog/2019/05/03/single-sign-on-sso-to-third-party-applications.html
- https://x.com/yunpark93
- https://www.linkedin.com/posts/yunpark93_life-update-i-founded-a-new-company-with-activity-7295954861878128640-5Fze
- https://www.tierzero.ai/blog/authors/yun-park/
- https://www.linkedin.com/posts/anhangzhu_two-years-ago-yun-park-and-i-set-out-to-activity-7485064126508212224-90UF
- https://www.tierzero.ai/blog/production-ai-agents-2026-landscape/
- https://www.linkedin.com/posts/yunpark93_databricks-reaches-38-billion-valuation-activity-6838504826347761664-ZfSO
- https://github.com/yunpark93
- https://www.linkedin.com/posts/yunpark93_introducing-devin-oncall-devin-automatically-activity-7516560458439557120-7Q4a
- https://x.com/yunpark93/status/2110800222339453129
- https://www.linkedin.com/posts/yunpark93_its-been-3-months-since-i-joined-cognition-activity-7505675229700976640-F4Qk
- https://www.linkedin.com/posts/yunpark93_two-years-ago-yun-park-and-i-set-out-to-activity-7485067083907645440-0hit
- https://x.com/yunpark93/status/2079298639986581580
- https://www.linkedin.com/posts/yunpark93_you-probably-saw-a-calendar-of-everything-activity-7442947010271506432-PONa
- https://www.linkedin.com/posts/yunpark93_one-thing-our-engineering-team-keeps-running-activity-7416884940027568128-by0y
- https://www.linkedin.com/posts/yunpark93_look-who-is-top-of-the-list-on-cursor-marketplace-activity-7458608439699656704-nTv2
- https://www.linkedin.com/posts/yunpark93_langsmith-for-startups-spotlight-tierzero-activity-7432852510153015297-s1NL
- https://www.linkedin.com/posts/yunpark93_how-tierzero-uses-agentic-memory-at-tierzero-activity-7401658917711462400-sB7e
- https://www.linkedin.com/posts/yunpark93_evaluating-ai-agents-can-be-trickyespecially-activity-7396947936284307456-rfVx
- https://www.linkedin.com/posts/yunpark93_every-week-our-a16z-team-publishes-a-new-activity-7442309756872105984-MEBa


Researched with Autumn (https://www.autumn.ai) from public sources. Updated 2026-11-04. Profile: https://www.autumn.ai/resources/cognition/people/yun-park · Everyone at Cognition: https://www.autumn.ai/resources/cognition/people