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AI Engineer Portfolio

Building explainable LLM, RAG, and agent systems for real-world use.

I am Neeraj Kumar Singh, an Applied AI / LLM engineer with 4+ years across NLP, explainable AI, model interpretability, production-oriented RAG systems, and backend AI tooling.

Portrait of Neeraj Kumar Singh

About

I work at the intersection of applied LLMs, trustworthy AI, and production engineering. My recent work includes LLM attribution, retrieval evaluation, agent workflows, and Python/PyTorch/FastAPI tooling that turns research ideas into usable systems.

Core stack

Python, PyTorch, FastAPI, LangGraph, LangChain, Hugging Face, PostgreSQL, Redis, ChromaDB, Elasticsearch, OpenTelemetry, and RAGAS.

Selected Projects

View all on GitHub

Dec 2025 - Mar 2026

XAI-RAG

Explainable retrieval-augmented generation system with hybrid search, retrieval attribution, and streaming FastAPI endpoints.

Combines ChromaDB, Elasticsearch, RRF, BGE re-ranking, DeBERTa NLI faithfulness checks, RAGAS, OpenTelemetry, Redis, and SSE delivery.

Open project

2026

Indic Research Agent

Public research assistant with Chainlit UI, LangGraph orchestration, LiteLLM model access, and typed search tools.

Uses query-kit provider search, PostgreSQL persistence, Redis caching, and streamed progress updates for research workflows.

Open project

2026

query-kit

Provider-agnostic Python CLI and library for searching public research sources with normalized text and JSON output.

Covers ACL Anthology, arXiv, PubMed, Semantic Scholar, and OpenReview with deduplication, filtering, and sync/async APIs.

Open project

2026

Explainable Agentic RAG

LangGraph workflow with typed tools, structured outputs, retrieval attribution, verifier/retry loops, and human review.

Evaluates faithfulness, context precision and recall, factual correctness, latency, and tool-call behavior for trustworthy RAG.

Open project

2024 - 2026

DLBacktrace

Model-agnostic interpretability framework for relevance tracing across MLPs, LLMs, and custom deep networks.

Benchmarked against SHAP, LIME, and Integrated Gradients; extended in production work for transformer and MoE attribution.

Open project

Published

SafeSpeech

Indic hate-speech mitigation pipeline for classification, explanation, and intensity-reduction suggestions.

Validated across five Indic languages with BERTScore results in the 0.96-0.99 range for mitigation quality.

Open project

Research and Technical Focus

LLM attribution and explainability for transformers, LLaMA-family models, and Mixture-of-Experts architectures

RAG and agent systems with hybrid search, retrieval attribution, verifier loops, and quality metrics

Backend AI delivery with Python, FastAPI, async APIs, tracing, persistence, caching, and deployment-ready tooling

Writing and Talks

A dedicated publications and talks index is being expanded. Current public activity and technical updates are available through the channels below.

Experience

Research Scientist, Lexsi AI

April 2024 - Present

Shipped DLBacktrace v2 for explainability across tabular, vision, NLP, and LLM workloads; expanded transformer and MoE support, compressed attribution traces 17-93x with low error, and built scalable visualization and trace-storage tooling.

Research Assistant (NLP Lab), CVPR Unit, Indian Statistical Institute

September 2021 - February 2024

Contributed to TrustED for trustworthiness evaluation in deep learning; developed explainable Indic hate speech detection and worked on an IC50 prediction web application integrating deep learning models.

Education

Master of Technology, Indian Statistical Institute

2019 - 2021

Percentage: 77.45

Bachelor of Technology, Bundelkhand Institute of Engineering & Technology

2015 - 2019

Percentage: 71.82

Let's connect

For AI engineering roles, collaboration, or technical discussion, reach out by email or LinkedIn.