Mark LaRosa

Partner @ Amplify Partners. Formerly Principal Solutions Architect at AWS, distributed systems junkie, fan/race driver of vehicles

[Jeff Martens @Jmartens]

I've been saying this all along. And the water that is *used* goes back to the water table, rivers, etc.

[Mark LaRosa @marklarosa]

@itunpredictable @dauber 5 foot 4 I didn’t know they stacked shit that high

[Mark LaRosa @marklarosa]

@dauber Turns out the answer is “why not both”

[Mark LaRosa @marklarosa]

I chose….wisely 🤣

[Mike Dauber @dauber]

Where you start your VC career can make or break it. Most people choose wrong. My thoughts after nearly twenty years of hiring and promoting junior VCs.

[Mark LaRosa @marklarosa]

This is truly insane if you have ever worked at this layer of infra in your past. While many on this platform often make outlandish claims about performance, meet someone who is actually delivering. It’s been a long time since I’ve seen a company care this much about efficiency and I hope we see more of it - but in the meantime you need to see what @LoopholeLabs is doing!

[Shivansh Vij @confusedqubit]

Not a bad cold boot time using FC's own benchmarking methodology.

Substrate is @LoopholeLabs's hypervisor, designed for the ground up for agents and agent platforms.

If you're building an agent platform, you deserve better than just another Firecracker/Cloud-Hypervisor wrapper

[Ryan Petersen @typesfast]

I will believe AI is driving productivity gains in the old economy when a front desk person checks me into a hotel with less than fifteen hundred keystrokes and mouse clicks.

[Jeff Martens @Jmartens]

This is a fantastic podcast episode for anyone in software!

[Mike Dauber @dauber]

I met @taiuti years ago when he was the cofounder of Luma. I knew it was only a matter of time until we got to work together again. Over the years there was only one person he spoke of to be his cofounder: @_bschmidtchen. When we all finally met and heard their vision for Reactor, it was a no brainer to co-lead the Seed with @buckymoore (finally!) and @theamberyang. We’re excited to be doubling down in the A and getting to work with this amazing team. A lot of great things are on the horizon for @reactorworld

[Mark LaRosa @marklarosa]

Very excited for this launch. Congrats @taiuti @_bschmidtchen

[reactor @reactorworld]

Today Reactor is coming out of stealth. We’ve raised $59M in Seed and Series A funding, led by @lightspeedvp, with participation from @AmplifyPartners, @wndrco, @Sky9Capital, and @FPVventures.

Reactor is the platform for building in the World Model era: the infrastructure that lets developers build with them at global scale for the first time. Stream from a frontier World Model to your app, in real time, all in under 10 lines of code.

World Models represent the next major shift in AI: pixels, audio and actions are generated on the fly, in real-time, in response to user inputs, and to the environment. Every time computing has made a shift from passive to interactive, entire industries appeared that didn't exist before. We're standing in front of such moment again.

Over the last 6 months, we’ve assembled an all-star team with alumni from Apple, Meta, Google, Luma AI, Netflix, and Replicate. We're already partnering with some of the biggest names and labs in the world, and hundreds of developers are already building on Reactor.

The World Model era starts now.

[Mark LaRosa @marklarosa]

@richardartoul Cali track days never smell like shit- you just need a venue change 🤣

[Mark LaRosa @marklarosa]

@turbochardo @richardartoul This is the way! Old BMWs too - some of the best cars ever made for driving and totally accessible. Just needs to be properly setup and maintained

[Mark LaRosa @marklarosa]

@richardartoul @turbochardo Yeah I wish!! Still hoping 🤣

[Mark LaRosa @marklarosa]

@richardartoul @turbochardo They’ve always been unobtainable. I had a Testarossa poster on my wall as a kid. Never imagined actually ever getting one

[Sarah Catanzaro @sarahcat21]

Agents’ data needs will become increasingly complex. I didn't get the filesystems thing at first. I thought it was just hype. But now I believe that file systems are better suited to agents than DBs or object stores. I'm less convinced that today's file systems are...the future.

Talking to senior folks building data infra, I heard some common refrains on why filesystems are right for agents:

1) Training corpora contain lots of file system operations – there are a lot of public Github repos containing file system operations, so these interactions appear frequently in data upon which models are trained. What’s more, filesystem semantics are dead simple. In contrast, database operations appear in training corpora but their semantics are kinda tricky; they are often missing critical context like schemas.

2) File systems do what agents need to work with data – agents typically need high-throughput, low-latency access to specific, small files containing unstructured data. Filesystems support this pattern well. Other data management systems don’t: OLTP databases require too much structure; object storage is too slow.

But while file systems seem to meet the needs of agents, that wil probably change imminently. Specifically, I expect agents will need 4 capabilities:

1) Transactions – when thousands of agents operate simultaneously, reading from and modifying shared state, and writing it back, the file system must store data reliably and mediate interactions between independent processes. Traditional distributed file systems weren't designed for highly concurrent, fine-grained mutation of shared state.

2) Queries – today, an agent might retrieve a single file and make a single update. But as agentic retrieval advances, agents will need to pull data from multiple files, materialize intermediate results, and run operations across those results. As Claude might say, this is not retrieval; it is a query problem.

3) ACLs – file systems do support ACLs, but they’re typically defined at the level of files, directories, users, and groups. Permissions are static, evaluated at access time, and don’t extend to how data is used once it’s read.

4) File scale – today’s agent workloads operate over small files, modest context windows, limited working memory, and bounded outputs. As models improve and context windows expand, agents will start working over much larger artifacts. A coding agent won’t operate file by file, it will need to understand and modify entire codebases.

There are teams starting to build the post-modern data stack for agents (so unoriginal, but I had to sneak some slop in here). @archildata gives agents fast, consistent access to data across environments, while explicitly meeting the latency requirements agents have and will have in the future. @SpiralDB built a columnar file format for extremely fast reads, including random access, selective reads, and large batch scans - it can give agents analytics capabilities.

To be honest, I’m in awe that data infra has held up so well as agents become more prevalent. But this won’t last forever. Agents will need more. Concurrency needs stronger guarantees. Retrieval becomes a query problem over unstructured data. Access control moves from static ACLs to dynamic, execution-aware policies. And file systems need to support efficient operations over much larger artifacts.

We’re starting to see early answers, but no dominant design. The choices we make now about how agents interact with data will harden quickly, so it’s worth getting them right.

More in my latest blog post: https://t.co/0nzCg4hGBZ

[Mark LaRosa @marklarosa]

@richardartoul They have to take a break from tweeting about how great FSD is while in their teslas being driven around by the equivalent of a 14 year old first time driver

[Mark LaRosa @marklarosa]

@richardartoul It’s like the definition of cool. Hard to think of things more cool. I mean I’m biased but so are most of the people I know, present company not excluded 🤣

[Mark LaRosa @marklarosa]

@richardartoul Sports cars are great but have you tried Kafka

[La Gazzetta Ferrari @GazzettaFerrari]

🚨 | Luca Cordero di Montezemolo on the new Ferrari Luce:

"If I said what I really think, I'd harm Ferrari. We're risking the destruction of a myth, I'm very sorry about that. I hope they at least remove the Prancing Horse from that car"

[Sunil Dhaliwal @dhaliwas]

Actually, not just getting started.

Been at this for 28 years.

Kinda tired. Might take a nap