Modal CEO on Agent Maxxing, the Future of Inference & Unpacking the Chaos of the GPU Market

Unsupervised Learning • • 59min → 5 min • #76
Modal CEO on Agent Maxxing, the Future of Inference & Unpacking the Chaos of the GPU Market
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Summary

  • This episode features Eric, founder and CEO of Modal, discussing the company’s three-year journey from a serverless compute platform to a multi-product AI infrastructure provider now at roughly $1B revenue run rate, covering GPU market dynamics, core technology investments, inference optimization, the rise of coding agents and sandboxes, neocloud economics, and future infrastructure bets.

Modal’s journey and product evolution

  • Modal started in late 2021 as a general-purpose serverless function platform for data, AI, and ML workloads, well before the ChatGPT moment.
  • The first major growth driver was Stable Diffusion hosting in 2022–2023, followed by expansion into audio, video, and adjacent generative AI use cases.
  • Modal deliberately began with a low-level compute primitive (serverless functions) to serve ML engineers and researchers who wanted to write code and move fast without managing infrastructure.
  • Early investments included a custom file system for fast container image loading and a custom container runtime and scheduler (no Kubernetes or Docker), which became foundational differentiators.
  • Sandboxes launched in 2023 as an asymmetric bet — low initial investment, high upside — anticipating code-generation use cases; they exploded in 2025 when models became proficient at writing code and now represent ~30% of revenue (~$300M run rate).
  • A dedicated training product was added recently, and the DeepSeek moment (early 2024) prompted a focused push into LLM inference, which also grew to ~30% of revenue.
  • Modal now offers a dedicated inference product (single-tenant deployments of state-of-the-art models with one click/CLI) and shared endpoints with token-based pricing, moving up the stack while leveraging its compute/storage foundation.
  • The long-term vision is a full portfolio of primitives for AI applications: compute, storage, serverless functions, sandboxes, training, inference, batch processing, and higher-level agent tooling.

GPU market dynamics and compute procurement

  • The GPU market remains highly fragmented and inefficient — “like an open-air drug market” — with deals often sourced through late-night WhatsApp groups, hotel lobby meetings, and personal networks (e.g., a VP’s cousin’s golf buddy).
  • Modal works with ~25 different cloud providers (including many neoclouds) and executes 2–3 compute deals per week, aggregating demand to manage capacity efficiently.
  • Compute is not a fungible commodity: it varies by chip type (H100, A100, B200, L40S, RTX Pro 6000, etc.), memory, networking, disk, location, and reliability.
  • Reliability is a major differentiator; neoclouds (often ex-crypto miners) frequently have failures — GPUs falling off the bus, node outages — and Modal automatically detects and routes around them.
  • Pricing data from third-party GPU marketplaces is moderately helpful for discovery but not fully trusted; internal pricing diverges from public listings, though external markets may mature over time.
  • Model-to-chip matching is largely memory-constrained: pick the cheapest GPU that fits the model’s memory requirement; Modal aims to automate this and dynamically shift workloads across GPU types to maximize utilization.
  • Older chips (Hoppers, A100s, L40S) remain heavily used for non-LLM workloads (audio, bio, smaller models) where they are more cost-efficient; H100s are still the most common GPU at Modal.
  • Modal is ramping aggressively on Blackwell (GB200) but sees sustained demand across the chip spectrum.

Core technology infrastructure

  • A massive source of alpha is willingness to build hard infrastructure: custom file system, container runtime, scheduler, and RDMA-based peer-to-peer data transfer between nodes.
  • This enables extremely fast cold starts (seconds for large models), CPU/GPU snapshotting, and rapid autoscaling — critical for both developer experience and production autoscaling.
  • The stack uses gVisor for isolation and recently added KVM for specific tasks; almost no off-the-shelf orchestration software.
  • These investments compounded over years and now yield unique performance (e.g., loading multi-hundred-GB models in seconds via RDMA) that is hard to replicate.

Inference optimization and unsolved problems

  • Inference remains an empirical science: teams read papers, test kernels, and iterate; Modal has 20–30 engineers focused solely on LLM performance.
  • Key techniques: disaggregated prefill (prefill on one node set, decode on another, connected via RDMA), KV cache optimization, quantization, mixture-of-experts routing.
  • The paradigm may shift (e.g., post-transformer architectures), so flexibility is essential; open-source engines (vLLM, SGLang) are now state-of-the-art and Modal contributes heavily to both rather than building proprietary alternatives.
  • Modal’s alpha lies in the infrastructure layer (autoscaling, scheduling, multi-cloud orchestration), so leaning into open-source inference engines is strategic.
  • Long-term, Modal wants to automate model-to-chip placement and dynamically shift workloads across heterogeneous GPU fleets to improve utilization and cost efficiency.

Multi-product strategy and customer examples

  • The durable differentiator is a multi-product platform, not just token serving (which is commoditizing via routers like OpenRouter).
  • Customers want a toolbox: sandboxes for code execution/RL rollouts, inference, training, batch processing, file storage — all integrated.
  • Major customers: Cognition (inference + sandboxes for RL), Ramp (background coding agents), Suno/Runway (generative audio/video), Decagon (voice/text support), DoorDash (internal LLM apps), 1X (robotics training), computational biotech firms (drug discovery, molecular sim), data-generation companies (benchmark environments).
  • Prioritization is ruthless: ~150 engineers, constant trade-offs, pausing projects when higher-ROI opportunities emerge; resource allocation is the CEO’s core job.
  • The roadmap is extensive; velocity is high but CI/CD and test infrastructure are under pressure as agent-generated code volume grows (est. 95% of merged lines agent-written).

Coding agents, sandboxes, and agent-native infrastructure

  • Sandboxes became the primitive for coding agents (rollouts, evals, agent orchestration); adoption was driven by senior engineers who treat agents as “10 interns” and use extensive test suites to guide them.
  • Junior adoption is lower; senior engineers benefit most from agent leverage.
  • Agents want the same things developers want: fast feedback loops, good errors, great docs — so Modal’s existing DX investments serve both.
  • Deprecation is harder: agents train on stale code, so Modal extended deprecation windows and runs automated pipelines where LLMs continuously write/run Modal code to catch breakage.
  • “Agent SEO” matters: ensuring LLMs recommend Modal in code-generation contexts creates a flywheel; incumbency in training data is a new moat.
  • Future agent infrastructure bets: low-latency real-time voice/video (CDN-like inference fabric), training/RL for mid-size models, full VM support (macOS, Windows, Android, iOS), durable object/workflow engines for agent orchestration — but the 5-year architecture is still unclear.

Neoclouds and GPU market structure

  • Neoclouds are essentially financing vehicles: they lease GPUs, raise debt against customer contracts, and operate at high leverage.
  • They are decent business models — GPU lifetimes and residual values have exceeded expectations — but structurally undifferentiated and capital-inefficient.
  • High cost of capital (vs. hyperscalers backed by massive cash flow) limits their scaling; some will fail and resell GPUs, creating a secondary market (“neo clouds” becoming “neo clouds”).
  • Implicit leverage: GPU commitments often require only ~30% upfront, creating future payment obligations dependent on continued VC fundraising.
  • Eric is bullish on AI demand overall but expects consolidation; not all neoclouds become trillion-dollar companies.

Future outlook and predictions

  • LLM model sizes will keep growing (pushing memory needs) until a paradigm shift; people use every bit of available memory.
  • Multimodal (voice-to-voice, real-time video) is severely underdeveloped — current voice assistants are “horrible” — and will drive demand for low-latency, globally distributed inference.
  • Robotics inference will be largely on-device, but training, simulation, and testing will run in the cloud.
  • Most companies won’t do custom post-training; the largest will (Cognition, Cursor), and they drive disproportionate token volume.
  • RL/post-training as a service faces a product-vs-services tension; Modal aims to productize it.
  • Every successful infra company becomes multi-product; Modal will own a large adjacent cluster (compute, storage, sandboxes, inference, training, agent tooling) but not everything (e.g., not model training, not applications).
  • GP rental prices in 12 months: likely higher, because Anthropic/OpenAI are profitable and have zero incentive to slow capacity acquisition.

Quickfire round insights

  • Biggest mind-change in the last year: sandbox opportunity size far exceeded expectations.
  • Hiring philosophy unchanged: agent productivity increases demand for engineers (Jevons paradox); short-term friction for new grads, long-term bullish on CS.
  • Biggest mistake: sequential thinking — in fast markets, must parallelize unblocked work instead of waiting for dependencies.
  • Swedish tech success: flywheel effect (success breeds success) + cultural entrepreneurial streak (Vikings to IKEA to Spotify to Lovable); Stockholm’s “delusional global ambition” is a feature.
  • Years 10–20: Modal as a conglomerate with many products, some moonshots; Eric stays involved in high-level resource allocation, less in day-to-day GPU contracting.
  • Call to action: pip install modal, build on Modal, reach out — Eric loves talking to customers.
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