jgrusewski 09b6bd6eaa feat(generalization): #32 gradient vaccine — mathematical overfit guarantee
Surgical gradient projection that makes overfitting mathematically
impossible. At each training step:
1. Save g_train (from CUDA Graph forward+backward)
2. Run SEPARATE non-graph forward+backward on vaccine batch → g_val
3. Compute dot(g_train, g_val) and |g_val|² via GPU reduction kernel
4. If dot < 0 (gradients DISAGREE), project out conflicting component:
   g_train -= (dot/|g_val|²) * g_val
5. Adam only sees gradient directions where train AND val agree

Two new CUDA kernels:
- gradient_dot_and_norm: parallel reduction with warp+block+atomicAdd
  Computes both dot product and norm² in single pass (bandwidth optimal)
- gradient_project: conditional SAXPY (skips when dot >= 0, no branch divergence)

The vaccine runs OUTSIDE the CUDA Graph (between replay_forward and
replay_adam) because it needs conditional logic. The non-graph vaccine
forward+backward reuses the same cuBLAS/loss/backward infrastructure.

Vaccine batch is sampled from the replay buffer alongside the training
batch and passed via FusedTrainingCtx::pending_vaccine_batch.

Config: enable_gradient_vaccine=false (default). Enable for mathematical
guarantee that no gradient update makes the model worse on held-out data.

Together with bottleneck (#31): "you can only remember 2 numbers, and
those 2 numbers must work on data you haven't trained on."

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-03-30 10:05:22 +02:00

Foxhunt

Production HFT trading system in Rust.

Architecture

The workspace contains 32 crates organized as follows:

Core Libraries (16)

Crate Purpose
trading_engine Order processing, FIX 4.4, IB TWS, SIMD, RDTSC timing
risk VaR, Kelly, circuit breakers, kill switches, compliance
risk-data Risk data types and shared structures
trading-data Trading data types
ml DQN Rainbow, PPO, TFT, Mamba2, ensemble inference
ml-data ML data types and feature definitions
data Market data ingestion and storage
backtesting Replay engine, strategy tester
adaptive-strategy Ensemble execution, microstructure analysis
common Shared types, resilience, error handling
storage S3 and local model storage
model_loader Model serialization and loading
market-data Market data feed handlers
database PostgreSQL access layer (SQLx)
config Configuration management
tli CLI commands and tooling

Services (8)

Service Purpose
backtesting_service gRPC backtesting service
broker_gateway_service FIX routing, broker connectivity
trading_service Core trading operations
ml_training_service Model training orchestration
data_acquisition_service Market data acquisition
trading_agent_service Autonomous trading agents
api_gateway gRPC API gateway with auth
web-gateway Axum REST + WebSocket gateway

Frontend

web-dashboard/ -- React 19 + TypeScript + Vite + TradingView charts.

Building

# Check compilation (no PostgreSQL required)
SQLX_OFFLINE=true cargo check --workspace

# Run tests for a specific crate
SQLX_OFFLINE=true cargo test -p <crate> --lib

# Clippy
SQLX_OFFLINE=true cargo clippy --workspace

ML Models

Four production model architectures on Candle v0.9.1 with CUDA:

  • DQN Rainbow -- Deep Q-Network with prioritized replay, dueling heads, noisy nets
  • PPO -- Proximal Policy Optimization with GAE and LSTM policies
  • TFT -- Temporal Fusion Transformer for multi-horizon forecasting
  • Mamba2 -- State space model for sequence prediction

Each model has a standalone trainer and a UnifiedTrainable adapter for the hyperopt pipeline.

Infrastructure

  • Git: Gitea at git.fxhnt.ai (Tailscale-only), Scaleway DEV1-S
  • Observability: OpenTelemetry OTLP (env OTEL_EXPORTER_OTLP_ENDPOINT)
  • Database: PostgreSQL with SQLx offline mode for CI

License

Proprietary. All rights reserved.

Description
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Readme 849 MiB
Languages
Rust 88.2%
Cuda 7.7%
Python 1.3%
Shell 1.1%
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