Companies

SF Tensor

sf-tensor.com

SF Tensor optimizes and operates cross-vendor AI training infrastructure so researchers can focus on model development.

HQSan Francisco, California, United States
Employees1-50
18 active roles
Jobs checked 3d ago
Specialization
Distributed Computing
Business
Software Applicationsand 2 more business values
  • Compute Hosting
  • Professional Services
Market
Software Developmentand 1 more market values
  • Scientific Research
Ecosystem
Not classified
Customers
Enterprisesand 1 more customers values
  • Researchers
More details
Organization type
Commercial Company
Ecosystem
Not classified
Business
Software Applications, Compute Hosting, Professional Services
Specialization
Distributed Computing
Market
Software Development, Scientific Research
Customers
Enterprises, Researchers
Delivery models
Hosted Software, Managed Compute, Professional Services
Revenue models
Services Fees
Listing status
Not classified
Latest equity round
Not classified
Reported funding amount
Not classified

About

SF Tensor builds an optimized, cross-vendor infrastructure stack for enterprise post-training and frontier pre-training, serving AI researchers, technology companies, and research institutions. Its platform selects cost-effective hardware, optimizes kernels across GPUs and TPUs, and manages distributed training runs, differentiating it by abstracting infrastructure complexity while charging based on verified savings.

Market

SF Tensor competes in AI/HPC infrastructure, particularly managed GPU training, cross-cloud compute orchestration, and software for enterprise post-training and frontier pre-training. It positions the SF Tensor Stack as an outcome-oriented, cross-vendor layer that handles hardware selection, distributed execution, kernel performance, checkpointing, and failure recovery. Compared with GPU clouds and AI acceleration platforms, it differentiates through workload-specific automatic kernel optimization, portability across NVIDIA, AMD, and TPU hardware, and a single workflow spanning 1 to 10,000 GPUs.

Target Customers

SF Tensor targets AI labs, frontier-model researchers, AI-native startups, and enterprise AI teams that need to pre-train or continuously post-train models without building a large infrastructure team. Likely buyers include AI/ML research leaders, CTOs, and infrastructure leaders responsible for reducing training costs, supporting proprietary-data workloads, and scaling across heterogeneous hardware.

At a Glance

Problem

SF Tensor addresses the infrastructure tax on AI model training. AI teams commonly spend engineering time optimizing code, managing GPU availability across cloud providers, debugging driver and distributed-training issues, and improving hardware utilization rather than advancing their models. The economic pain is direct: compute is expensive, NVIDIA supply is constrained, and vendor lock-in limits access to cheaper alternatives. SF Tensor claims its approach can reduce training-run costs by an average of 70% and compress the path from a working research repository to a managed training fleet from months to hours.

The clearest use case is taking a proprietary dataset or a novel model architecture and turning it into a specialist model or frontier-scale training run without building a large infrastructure team. For enterprises, this means repeatedly post-training smaller models on underwriting, clinical, industrial, or other private data and deploying the resulting weights under the organization’s own controls; for AI labs, it means scaling experiments from one GPU to thousands without infrastructure becoming the bottleneck.

Product / Service

SF Tensor offers an optimized, cross-vendor training stack centered on Tensor Cloud, a Kernel Optimizer, and its Emma hardware-aware programming language. Customers bring their model, data, repository, budget, and target GPU count; SF Tensor compiles and optimizes the kernels, identifies the cheapest capable hardware across providers, and operates the run. Tensor Cloud handles orchestration, placement, checkpointing, and recovery from failures, while the system’s kernel optimizer uses detailed hardware benchmarking to find efficient implementations across different accelerators.

The delivery model ranges from a self-service cloud product with Basic, Pro, and Enterprise tiers to a forward-deployed service with dedicated engineering support, custom kernel optimization, private-cloud deployment, and runs of up to 10,000 GPUs. The benefit is to buy a training outcome rather than manage infrastructure: teams can use one workflow across vendors, run in SF Tensor’s cloud or their own, preserve control over private data and model weights, and improve both iteration speed and compute economics.

Market

SF Tensor competes in AI infrastructure, specifically managed model-training platforms, GPU-cloud orchestration, cross-vendor accelerator portability, and compiler or kernel optimization. The company’s positioning is broader than simple GPU rental because it combines hardware selection and job orchestration with low-level workload optimization. The gathered evidence does not name a one-for-one competitor, but Modal is a clear adjacent competitor in AI cloud infrastructure because it also offers training, inference, batch processing, and scalable compute; SF Tensor also competes indirectly with vendor-specific stacks and GPU-cloud providers that offer access to NVIDIA and alternative AMD, Google, and Amazon accelerators.

The company appears to be at an early commercial stage rather than having demonstrated mature revenue traction. Its Tensor Cloud launch was described as a private beta in October 2025, and its launch materials sought early collaborators. YC lists SF Tensor as founded in 2025 in its Fall 2025 batch, while the company says it is backed by Y Combinator and Susa Ventures. The public evidence gathered does not disclose named customers, revenue, or production usage metrics, so the strongest visible traction is product launch, investor backing, and development of an enterprise and frontier-lab offering rather than verified commercial scale.

Founders & Leadership

Ben KoskaFounder
Founder & CEO
Tom KoskaFounder
Founder
Luk KoskaFounder
Founder

Funding History

2025-01
Accelerator/Incubator$500K total reported; round amount undisclosed

Y Combinator

2025-12
Early Stage VCUndisclosed

Susa Ventures, Transpose Platform Management

Recent News

2026-09-25other
SF Tensor reports first-place results on SOL-ExecBench

SF Tensor reported that it ranked first on NVIDIA's SOL-ExecBench across all four tracks. The company presented its benchmark result and lessons learned in a public post.

2025-12-19funding
SF Tensor records $500K in early-stage venture financing

PitchBook records a completed early-stage venture financing for SF Tensor dated December 19, 2025, and reports that the company has raised $500,000.

2025-09-13other
Why We're Building SF Tensor

SF Tensor outlined its broader stack: Emma, a hardware-agnostic programming language; elastic cross-cloud compute; and automated kernel optimization. The company also opened the door to early collaborators.

Active Roles

18
San Francisco/Engineering/17d ago
San Francisco/Engineering/17d ago
San Francisco/Engineering/17d ago
San Francisco/Engineering/17d ago
San Francisco/Data & Analytics/17d ago
San Francisco/Data & Analytics/17d ago
Mathematical StaffSan Francisco, CA/Data & Analytics/21d ago
Technical Staff, Post/Data & Analytics/40d ago
Technical Staff, AI/Engineering/40d ago
Technical Staff, Product/Engineering/40d ago
GPU KernelsSan Francisco, CA/Engineering/40d ago
GPU CompilerSan Francisco, CA/Engineering/40d ago
Technical Staff, Sandbox/Engineering/40d ago
Founding GPU Compiler EngineerSan Francisco, CA/Engineering/77d ago
Founding GPU Compiler EngineerSan Francisco, CA/Engineering/77d ago
Founding GPU Compiler EngineerSan Francisco, CA/Engineering/77d ago

Business Model

SF Tensor charges a share of verified customer savings against baseline compute costs; customers do not pay if SF Tensor does not reduce their bill. It also offers tiered Tensor Cloud plans and forward-deployed enterprise infrastructure and engineering support.

Products

Tensor Cloud: managed cross-cloud compute orchestration for training runsKernel Optimizer: workload-specific, topology-aware kernel compilation and optimizationEmma Language: a portable programming language targeting GPUs, TPUs, and future acceleratorsForward-Deployed: enterprise-scale training support with dedicated infrastructure control and engineering assistance

Tech Stack

Emma programming languagePyTorch integrationAutomatic kernel optimizationTopology-aware microbenchmarking across cache, memory, and inter-core systemsCross-cloud GPU orchestrationNVIDIA, AMD, and TPU supportDistributed training from 1 to 10,000 GPUsSpot-instance migration, checkpointing, and failure recovery

Competitors

Modal
Lambda
RunPod
Together AI
CoreWeave