Dev Gupta

Projects

Things I built because I wanted them to exist. Each has a write-up covering the decisions and the tradeoffs, not just the outcome.

2025

Unified ML Feature Store

One feature definition serving both real-time inference and historical training queries, so the two never drift apart.

  • Point-in-time-correct retrieval, so training sets cannot leak the future
  • Redis online store at 4 ms p99 for 100-entity batch lookups
  • 62 tests across Python 3.10-3.12 in CI, with ruff and mypy
  • Python
  • PostgreSQL
  • Redis
  • FastAPI
  • Docker
  • Terraform
  • Prometheus
  • Typer

Read the case study

2025

Multimodal Video Q&A Engine

Ask a question about an uploaded video and get an answer with timestamped citations back to the footage it came from.

  • Audio and visual context fused into one queryable representation
  • Retrieval without embeddings, via a cost-tiered two-stage LLM cascade
  • Answers streamed over SSE with live token-cost accounting
  • Python
  • FastAPI
  • Next.js
  • TypeScript
  • Whisper
  • MoviePy
  • OpenAI API
  • SSE

Read the case study

2025

GNSS/INS Sensor Fusion Filter

An error-state Kalman filter in Rust that fuses inertial and GNSS measurements, written to learn state estimation properly.

  • Error-state EKF so the filter linearises around a nominal trajectory instead of the full nonlinear dynamics
  • High-rate IMU propagation corrected by sparse GNSS updates, with quaternion attitude via nalgebra
  • Python simulation harness for ground-truth replay, plus criterion benches on the Rust hot path
  • Rust
  • nalgebra
  • Python
  • criterion

Read the case study