Renen Hallak

Founder & CEO VAST Data

Last Reviewed: September 19, 2026

Executive Summary

Renen Hallak founded VAST Data in January 2016 on a contrarian architectural bet: that the decades-old storage tiering hierarchy — fast expensive media for hot data, slow cheap media for cold — could be collapsed entirely if you rethought the system around commodity flash and disaggregated shared-everything design. The bet was made before the AI training boom, and the boom has since made it look prescient, because training clusters need exactly what tiering cannot give them, which is uniform high-throughput access to everything at once. VAST is now a principal storage supplier to the large AI compute operators, counting CoreWeave, xAI, Mistral Compute and the US Air Force among its customers, and in April 2026 it raised $1bn at a $30bn valuation with Nvidia among the backers. Hallak came to the problem from XtremIO, where he had already run the R&D organisation that built one of the first successful all-flash arrays.

Career Highlights

• Founder and chief executive of VAST Data since January 2016, alongside co-founders Shachar Fienblit, Jeff Denworth and Alon Horev.
• Raised a $1bn Series F in April 2026 at a $30bn valuation, backed by Nvidia, Drive Capital, Access Industries, Fidelity and NEA — a step up from the $9.1bn valuation at the 2023 Series E.
• Grew the business from $1bn cumulative software bookings and $200m ARR in 2023 to over $4bn cumulative bookings and more than $500m committed ARR by April 2026.
• Signed a $1.17bn agreement with CoreWeave; other named customers include xAI, Mistral Compute, Sharon AI, Megaport, Cursor and the US Air Force.
• Vice president of research and development at XtremIO, responsible for architecture and development of an all-flash array that reached over $1bn in revenue, leading more than 200 engineers.
• Named among Goldman Sachs’ 100 Most Intriguing Entrepreneurs.

Professional Journey

Hallak’s early career was in systems software rather than storage specifically. He worked on a content distribution system at Intercast, and served on the CTO team at Time to Know, an education technology company — the kind of small, architecture-heavy roles that tend to produce people comfortable rebuilding a stack from first principles.

XtremIO was where that became a discipline at scale. He ran research and development there through the period in which all-flash arrays went from a contested idea to the default for primary enterprise storage, overseeing the architecture and development of a product that passed $1bn in revenue and an engineering organisation of more than two hundred people. EMC acquired XtremIO in 2012, and the product became one of the more successful storage acquisitions of its era.

In January 2016 he left to found VAST Data with Shachar Fienblit, Jeff Denworth and Alon Horev. The thesis was that the storage tiering model — the assumption that you must choose between fast and cheap and therefore must constantly move data between tiers — was an artefact of media economics that no longer held, and that a disaggregated, shared-everything architecture built on commodity flash could serve all data at one tier. That removes an entire class of operational complexity, and it happens to be precisely what large-scale AI training workloads require, since they read across the whole dataset rather than a working set.

Funding tracked the thesis being proved slowly and then quickly: $15m in 2016, $25m in 2018, $40m in 2019, $100m in 2020, $83m in 2021, then $118m in 2023 at a $9.1bn valuation. The Series F in April 2026 was a different order of magnitude — $1bn raised at $30bn, with Nvidia, Drive Capital, Access Industries, Fidelity and NEA participating — reflecting the company’s position inside the AI infrastructure buildout. The commercial numbers moved with it, from $1bn cumulative software bookings and $200m ARR in 2023 to over $4bn cumulative bookings and more than $500m in committed ARR three years later, anchored by agreements such as the $1.17bn deal with CoreWeave.

The company is Israeli-American, headquartered in New York City, with Michael Wing, formerly of Dell EMC, as president. Hallak has been named among Goldman Sachs’ 100 Most Intriguing Entrepreneurs.

Education

Hallak holds a BA and an MSc in Computer Science, both awarded summa cum laude. No source located for this profile names the institution that awarded either degree, or the years, so neither is recorded here.