NVIDIA GPU Infrastructure

End-to-End GPU-Accelerated AI Stack

Every layer of TimeStack's intelligence pipeline — from raw behavioral signal ingestion to real-time personalized inference — is built on NVIDIA's accelerated computing platform. We don't use GPUs as an accessory; they are the computational foundation that makes behavioral AI at scale possible.

Large-Scale Model Training on NVIDIA H100 & H200 Clusters

Our custom behavioral models are trained on multi-node GPU clusters, leveraging NVIDIA's full training stack for maximum throughput and model quality.

Multi-Node Distributed Training

TimeStack's behavioral LLM requires training on diverse, high-volume behavioral corpora spanning goal-setting theory, coaching methodologies, productivity research, behavioral psychology, and millions of anonymized behavioral sequences. This demands GPU-scale compute.

Our training infrastructure runs on NVIDIA H100 SXM5 and H200 SXM GPUs in multi-node configurations, using NVLink and NVSwitch for high-bandwidth inter-GPU communication. We employ 3D parallelism — combining tensor, pipeline, and data parallelism — to efficiently scale training across nodes while maintaining model convergence.

Primary GPUs NVIDIA H100 80GB SXM5, H200 141GB SXM
Interconnect NVLink 4.0 (900 GB/s), NVSwitch
Parallelism 3D: Tensor + Pipeline + Data (FSDP)
Precision BF16 mixed-precision with loss scaling
Framework NVIDIA NeMo + Megatron-LM
Checkpointing Distributed checkpointing with async I/O
Training Cluster Topology
Node 0
H100
H100
H100
H100
NVLink 4.0
Node 1
H100
H100
H100
H100
NVLink 4.0
8x H100 80GB per training run, scaling to 32+ GPUs for full pre-training

Custom LLM Development with NeMo Framework

NVIDIA NeMo is the backbone of our LLM training pipeline — from data curation through alignment, enabling rapid iteration on domain-specific behavioral models.

01

Data Curation & Preprocessing

NeMo Data Curator processes our behavioral training corpus — filtering, deduplicating, and quality-scoring millions of documents spanning behavioral psychology literature, coaching transcripts, goal-setting frameworks, and structured behavioral logs. GPU-accelerated text processing via RAPIDS achieves 40x throughput over CPU pipelines.

NeMo Data Curator RAPIDS cuDF Quality Filtering
02

Continued Pre-training

Starting from a LLaMA-3 base checkpoint, we perform continued pre-training on our curated behavioral corpus to inject domain knowledge. The model learns behavioral ontologies, temporal reasoning patterns, and the causal structure of human life domains. We use Megatron-LM's efficient attention implementations with FlashAttention-2 for 2.5x training speedup.

Megatron-LM FlashAttention-2 BF16 Mixed Precision
03

Supervised Fine-tuning (SFT)

Task-specific fine-tuning using curated instruction datasets for behavioral coaching, goal decomposition, domain classification, and temporal planning. We employ LoRA (rank 64) and QLoRA adapters to efficiently train multiple task-specific variants from a single base model, reducing per-task GPU memory requirements by 75%.

LoRA / QLoRA Multi-task SFT Instruction Tuning
04

RLHF Alignment

Reinforcement Learning from Human Feedback aligns the model with effective coaching behaviors. Our reward model is trained on expert behavioral coach evaluations, optimizing for intervention quality, empathy calibration, and long-term behavioral outcome prediction. We use NeMo-Aligner with PPO for stable training.

NeMo-Aligner PPO Optimization Reward Modeling
05

Evaluation & Deployment

Comprehensive evaluation against behavioral coaching benchmarks, safety filters, and domain-specific accuracy tests. Passing models are compiled through TensorRT-LLM for optimized inference and deployed via Triton Inference Server with automatic scaling based on request load.

TensorRT-LLM Triton Server NVIDIA NIM

TensorRT & TensorRT-LLM for Production Inference

Real-time behavioral AI demands sub-100ms response times. TensorRT compilation and quantization make this possible at scale.

LLM Inference: TensorRT-LLM

Our behavioral LLM is compiled through TensorRT-LLM with in-flight batching, paged KV-cache, and speculative decoding. This achieves 3.5x throughput improvement over standard HuggingFace inference while reducing per-token latency to 12ms on H100.

3.5x Throughput Gain
12ms Per-token Latency
60% Memory Reduction

Prediction Models: TensorRT

Non-LLM models (temporal prediction, GNN, NLP classifiers) are compiled to TensorRT engines with INT8 calibration. Post-training quantization with minimal accuracy loss (<0.3% on behavioral benchmarks) enables serving on smaller GPU instances for cost efficiency.

8x vs. PyTorch
<5ms Prediction Latency
0.3% Accuracy Impact

Embedding Models: Optimized Retrieval

Our behavioral embedding models (used for semantic search over user histories, goal matching, and similar-user clustering) are compiled to TensorRT FP16 engines with dynamic batching, enabling real-time retrieval from our pgvector store.

5x Embedding Speed
<2ms Encode Latency
768d Vector Dimension

Multi-Model Serving with Triton Inference Server

A single user request can trigger 4-6 model inferences. Triton orchestrates this model ensemble with intelligent scheduling and resource allocation.

Client Request
User check-in: "Feeling burned out, skipped my workout, can't focus at work"
Triton Inference Server — Model Ensemble
Step 1
NLP Classifier

Sentiment extraction, domain tagging (Health, Career), intent detection

3ms
Step 2
Embedding Model

Encode input to behavioral vector, retrieve historical context from vector store

2ms
Step 3a
Wellbeing Sentinel

Anomaly detection — burnout probability scoring against user baseline

4ms
Step 3b
DomainGraph GNN

Cross-domain impact: Health decline → Career impact prediction

5ms
Step 3c
Chronos TFT

Temporal prediction: energy forecast, optimal recovery window

4ms
Step 4
TimeStack LLM

Generate personalized coaching response with full behavioral context

~200ms
Response
Personalized intervention with burnout risk score, recovery plan, domain rebalancing suggestions, and adjusted weekly goals — all grounded in the user's behavioral history
Ensemble Scheduling

Directed acyclic graph (DAG) execution enables parallel model inference where dependencies allow, reducing end-to-end latency by 40%.

Dynamic Batching

Request aggregation across concurrent users maximizes GPU utilization. Configurable max latency thresholds ensure SLA compliance.

Model Versioning

Zero-downtime model updates with automatic canary routing. A/B testing infrastructure enables continuous model improvement in production.

Auto-scaling

Kubernetes HPA with GPU utilization metrics scales Triton instances from 1 to N based on request load, optimizing cost and latency.

GPU-Accelerated Data Pipelines with NVIDIA RAPIDS

Behavioral data is high-volume, multi-modal, and time-sensitive. RAPIDS transforms our data engineering from a bottleneck into a competitive advantage.

cuDF

Behavioral Feature Engineering

GPU-accelerated DataFrames process millions of behavioral events per minute — computing rolling statistics, temporal features, cross-domain aggregations, and streak calculations. A feature pipeline that took 45 minutes on CPU completes in 68 seconds on a single H100.

40x faster than pandas
cuML

User Clustering & Segmentation

GPU-accelerated K-Means, DBSCAN, and UMAP for real-time user cohort identification. We cluster users by behavioral patterns to identify similar profiles for cold-start recommendations and federated model grouping.

25x faster than scikit-learn
cuGraph

Social Graph Analysis

GPU-accelerated graph analytics for our accountability tribe network — computing influence propagation, community detection, and optimal peer-matching using PageRank and Louvain community detection on the full user graph.

50x faster than NetworkX

Proprietary CUDA Kernels for Behavioral Operations

Where off-the-shelf GPU operations don't meet our needs, we develop custom CUDA kernels optimized for behavioral AI workloads.

Cross-Domain Sparse Attention

Our DomainGraph model uses a custom attention pattern where each life domain attends to all others through learned causal masks. Standard dense attention is wasteful for this structured graph — our sparse CUDA kernel achieves O(n) complexity vs O(n^2), enabling real-time inference on mobile-proxied requests.

kernel signature
__global__ void cross_domain_sparse_attn(
    const float* Q,      // [batch, 8, d_model]
    const float* K,      // [batch, 8, d_model]
    const float* V,      // [batch, 8, d_model]
    const int*   mask,   // [8, 8] learned causal mask
    float*       out,    // [batch, 8, d_model]
    int d_model
);

Temporal Windowed Convolution

Custom 1D convolution kernel with variable-length temporal windows for processing behavioral time series at multiple scales simultaneously. Handles irregular time intervals (real human behavior doesn't follow fixed schedules) through learned time-aware position encodings computed on GPU.

kernel signature
__global__ void temporal_windowed_conv(
    const float*  signal,      // [batch, seq_len, features]
    const float*  timestamps,  // [batch, seq_len]
    const float*  kernels,     // [n_scales, kernel_size]
    float*        output,      // [batch, seq_len, n_scales * features]
    int n_scales,
    int kernel_size
);

Personalized Embedding Update

Online learning kernel that incrementally updates per-user behavioral embeddings without full model retraining. Uses exponential moving averages with adaptive learning rates computed per-dimension, enabling the model to rapidly adapt to behavioral shifts (e.g., new job, life event) while maintaining long-term stability.

kernel signature
__global__ void personalized_embed_update(
    float*       user_embed,   // [d_embed] persistent
    const float* new_signal,   // [d_embed] from latest
    const float* lr_per_dim,   // [d_embed] adaptive rates
    float        momentum,
    float        decay
);

Production Deployment with NVIDIA NIM

NVIDIA NIM containers package our optimized models as production-grade microservices with enterprise reliability.

Containerized Model Services

Each model (LLM, Chronos, DomainGraph, NLP pipeline) runs as an isolated NIM container with its own resource allocation, health checks, and scaling policies. Kubernetes orchestration enables independent scaling per model based on demand patterns.

Canary Deployments

New model versions are deployed to 5% of traffic initially, with automated metrics monitoring (latency, accuracy, user engagement). Gradual rollout to 100% only after statistical significance thresholds are met across all behavioral quality metrics.

Multi-Region Serving

NIM containers deployed across US, EU, and APAC regions with request routing based on user location. Ensures GDPR compliance by keeping EU user data and inference within EU boundaries while maintaining <100ms end-to-end latency globally.

Observability & Monitoring

Built-in Prometheus metrics for GPU utilization, inference latency (p50/p95/p99), throughput, queue depth, and model accuracy drift. Grafana dashboards with PagerDuty alerting ensure 99.9% inference availability SLA.

The Complete NVIDIA Technology Stack

From research to production, every component of our AI infrastructure leverages NVIDIA's accelerated computing ecosystem.

Hardware
H100 80GB SXM5 H100 SXM5 NVLink 4.0 NVSwitch InfiniBand HDR
Training
NeMo Framework Megatron-LM NeMo-Aligner NeMo Data Curator FlashAttention-2
Optimization
TensorRT TensorRT-LLM INT8 / FP16 Quantization Graph Optimization Kernel Auto-tuning
Serving
Triton Inference Server NVIDIA NIM Dynamic Batching Model Ensembles Kubernetes + GPU Operator
Data
RAPIDS cuDF RAPIDS cuML RAPIDS cuGraph Custom CUDA Kernels GPU-accelerated pgvector

Built for GPU-Scale Intelligence

TimeStack's behavioral AI would not be possible without NVIDIA's accelerated computing platform. Every model we train, every prediction we serve, and every insight we generate runs on GPU infrastructure.