Zack Tembi

Navigating the future of AI

📍 United States🔄 Updated September 2026💼 12 investments📅 8 years investing🗓 Last invested Jun 2025
Operator-angel🌍 United States
12
Total investments
2
Early stage
4
Mid stage
2
Late stage
8y
Years active

Portfolio

11 investments · sorted by recency
All investments
Early stage
Mid stage
Late stage
Investor
Jun 2025
Cerebras Systems is the worlds fastest AI inference. We are powering the future of generative AI. We’re a team of pioneering computer architects, deep learning researchers, and engineers building a new class of AI supercomputers from the ground up. Our flagship system, Cerebras CS-3, is powered by the Wafer Scale Engine 3—the world’s largest and fastest AI processor. CS-3s are effortlessly clustered to create the largest AI supercomputers on Earth, while abstracting away the complexity of traditional distributed computing. From sub-second inference speeds to breakthrough training performance, Cerebras makes it easier to build and deploy state-of-the-art AI—from proprietary enterprise models to open-source projects downloaded millions of times. Here’s what makes our platform different: 🔦 Sub-second reasoning – Instant intelligence and real-time responsiveness, even at massive scale ⚡ Blazing-fast inference – Up to 100x performance gains over traditional AI infrastructure 🧠 Agentic AI in action – Models that can plan, act, and adapt autonomously 🌍 Scalable infrastructure – Built to move from prototype to global deployment without friction Cerebras solutions are available in the Cerebras Cloud or on-prem, serving leading enterprises, research labs, and government agencies worldwide. 👉 Learn more: www.cerebras.ai Join us: https://cerebras.net/careers/
Investor & Advisor
May 2025
Aegis AI is an AI-native Email Security platform. Our AI agents think like human analysts—stopping Zero-day Phishing, BEC, and Malware attacks while cutting false positives by up to 90%.
Investor
Feb 2025
Openlayer is an evaluation workspace for AI. Startups and Fortune 500s alike use Openlayer to run tests, track and version models, and monitor production requests.
Investor
Feb 2025
Sinaptica Therapeutics™ is a Cambridge MA-based, clinical-stage company that has developed a personalized closed-loop neuromodulation therapy for Alzheimer’s Disease (AD). The company was founded by two top clinical researchers in the field of noninvasive brain modulation for neurodegenerative disorders, together with support from biotech, digital health, and medical device industry executives. The company’s SinaptiStim™ System represents a totally new approach to treating AD by enhancing neuroplasticity via neurostimulation of key brain networks involved in memory, and has been granted FDA Breakthrough Designation based on unprecedented published Phase 2 sham-controlled data that achieved statistical significance on all four gold-standard cognitive & functional clinical endpoints. Sinaptica is building upon over a decade of research on innovative brain targeting methods, biophysical modeling, and noninvasive treatment protocols leveraging machine learning on proprietary datasets to create a foundational leap in personalized precision electromagnetic therapeutics. Based on highly significant published sham-controlled data, the companys neurostimulation device and integrated personalization engine has the potential to become one of the most clinically-effective treatments to reach Alzheimer’s patients in over two decades, and is protected by multiple pending patents.
Investor & Advisor
Oct 2024
At the forefront IoT, Amyna Systems advances the industry with revolutionary technologies.
Investor (Acquired by Drata)
Feb 2024
SafeBase empowers organizations to develop a customer-facing, scalable Trust Center that automates the security review process between buyers and sellers. Fast-growing companies like LinkedIn, Asana, Palantir, and Jamf use SafeBase to reduce security questionnaires, create a better buying experience, accelerate sales velocity, and position security as a revenue driver. To learn more, visit drata.com.
Investor
Feb 2024
OUR MISSION IS SIMPLE: GIVE YOU MORE CONTROL OF YOUR CLOUD SERVICES SO YOU SPEND LESS What started as a simple idea has grown into an imaginative set of industry-leading solutions that empower FinOps teams to manage the cloud from a single console easily. With Vega, you get more options and more control to spend much less time and money.
Investor & Advisor
Jan 2024
LOKKER was founded as a targeted response to the proliferation of online scams, spam, and exploitation of personal data. Laser-focused on online privacy, we provide state-of-the-art SaaS solutions to corporate marketers and tech teams—providing modern tools to deliver safer and more private web experiences. We help companies dramatically improve online and mobile experiences by protecting their websites and their customers. At LOKKER, we power privacy.
Investor & Advisor
Dec 2023
In the era of AI, knowing what’s real is harder than ever. Social engineering threats are sophisticated, multi-channel campaigns. They lurk in your inbox, compromise your email channels, and weaponize fake profiles across social networks to deceive and defraud your people and your brands. Doppel is the agentic social engineering defense platform built to fight AI with AI. Unlike traditional systems that stop at detection and inbox scoring, Doppel delivers real-time disruption. We secure the inbox while executing automated takedowns on malicious sending infrastructures, lookalike domains, and rogue profiles at machine speed. By unifying Digital Risk Protection, Human Risk Management, and Email Security onto a single centralized platform, Doppel shuts down threats at their source. We safeguard every channel, move faster than attack speed, and turn global threat intelligence into a compounding network effect that keeps you ahead of the curve. Backed by Bessemer Venture Partners, a16z, George Kurtz - CEO, CrowdStrike, South Park Commons, Strategic Cyber Ventures, Aurum Partners, a group of athlete investors led by WNBA players Nneka Ogwumike, Breanna Stewart, and Kelsey Plum, who joined the round through the a16z Cultural Leadership Fund, Script Capital, 9Yards Capital, Sozo Ventures, NTT DOCOMO Ventures, and SVAngel.
Investor
Oct 2023
We help companies create personalized, scalable audio content. Our first product helps brands deliver one-on-one voice messages to their audiences. Were backed by Colle Capital and UpHonest Capital.
Investor
2018
Cribl, the Data Engine for IT and Security, empowers organizations to transform their data strategy. Powered by a data processing engine purpose-built for IT and Security, Cribl’s product suite is a vendor-agnostic data management solution capable of collecting data from any source, processing billions of events per second, automatically routing data for optimized storage, and analyzing any data, at any time, in any location. With Cribl, IT and Security teams have the choice, control, and flexibility required to adapt to their ever-changing data needs. Cribl’s offerings–Stream, Edge, and Search–are available either as discrete products or as a holistic solution.
Experience · 13 entries
All (13)
Investments (12)
Founder (1)
2025
Investor
Jun 2025
Cerebras Systems is the worlds fastest AI inference. We are powering the future of generative AI. We’re a team of pioneering computer architects, deep learning researchers, and engineers building a new class of AI supercomputers from the ground up. Our flagship system, Cerebras CS-3, is powered by the Wafer Scale Engine 3—the world’s largest and fastest AI processor. CS-3s are effortlessly clustered to create the largest AI supercomputers on Earth, while abstracting away the complexity of traditional distributed computing. From sub-second inference speeds to breakthrough training performance, Cerebras makes it easier to build and deploy state-of-the-art AI—from proprietary enterprise models to open-source projects downloaded millions of times. Here’s what makes our platform different: 🔦 Sub-second reasoning – Instant intelligence and real-time responsiveness, even at massive scale ⚡ Blazing-fast inference – Up to 100x performance gains over traditional AI infrastructure 🧠 Agentic AI in action – Models that can plan, act, and adapt autonomously 🌍 Scalable infrastructure – Built to move from prototype to global deployment without friction Cerebras solutions are available in the Cerebras Cloud or on-prem, serving leading enterprises, research labs, and government agencies worldwide. 👉 Learn more: www.cerebras.ai Join us: https://cerebras.net/careers/
Investor & Advisor
May 2025
Aegis AI is an AI-native Email Security platform. Our AI agents think like human analysts—stopping Zero-day Phishing, BEC, and Malware attacks while cutting false positives by up to 90%.
Investor
Feb 2025
Openlayer is an evaluation workspace for AI. Startups and Fortune 500s alike use Openlayer to run tests, track and version models, and monitor production requests.
Investor
Feb 2025
Sinaptica Therapeutics™ is a Cambridge MA-based, clinical-stage company that has developed a personalized closed-loop neuromodulation therapy for Alzheimer’s Disease (AD). The company was founded by two top clinical researchers in the field of noninvasive brain modulation for neurodegenerative disorders, together with support from biotech, digital health, and medical device industry executives. The company’s SinaptiStim™ System represents a totally new approach to treating AD by enhancing neuroplasticity via neurostimulation of key brain networks involved in memory, and has been granted FDA Breakthrough Designation based on unprecedented published Phase 2 sham-controlled data that achieved statistical significance on all four gold-standard cognitive & functional clinical endpoints. Sinaptica is building upon over a decade of research on innovative brain targeting methods, biophysical modeling, and noninvasive treatment protocols leveraging machine learning on proprietary datasets to create a foundational leap in personalized precision electromagnetic therapeutics. Based on highly significant published sham-controlled data, the companys neurostimulation device and integrated personalization engine has the potential to become one of the most clinically-effective treatments to reach Alzheimer’s patients in over two decades, and is protected by multiple pending patents.
Investor
2025
Were changing the world of events. Events.com helps event organizers save time and make more money and provides event-goers access to virtual and in-person experiences theyll love.
Show all 13 entries ↓
Investment activity
2018–2025 · 12 investments
20181202322024420255
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