AI Engineer

Sajjad Haider Khan

I design and ship GenAI-powered systems that think, learn, and run reliably in production — not just in a notebook.

AI Engineering GenAI Azure Backend Microservices

About

I'm an AI Engineer who builds full-stack, production-grade systems — from data architecture to the LLM pipelines that make them intelligent. My background spans an MSc in Data Science & Computational Intelligence and a B.Tech in Computer Science & Engineering, but I learn fastest by shipping real systems rather than tutorials.

AQLedger, my flagship project, was designed, built, and deployed solo end-to-end — architecture, backend, database, AI pipeline, and infrastructure. I care about systems that are genuinely production-ready: structured LLM outputs over loose prompting, cost-aware AI pipelines that don't burn money by default, and infrastructure that's boring in the best way — reliable, observable, and secure.

Use Cases

Where GenAI meets real backend engineering.

Automated Data Classification

Turn unstructured, free-text input into structured, schema-validated data using LLMs with strict JSON Schema outputs — eliminating the inconsistent-value problems loose prompting causes.

Self-Learning Systems

Historical-lookup caches that get faster and cheaper the more they're used — falling back to LLM reasoning only for genuinely new patterns.

Cost-Aware AI Pipelines

User-facing controls over which AI stages actually run — so AI cost scales with real need instead of blanket automation.

Secure Cloud Infrastructure

Least-privilege identity design and secrets that never touch source control — backed by Azure Key Vault and scoped service identities.

Case Studies

Live Project

AQLedger

A self-learning personal finance ledger — every transaction is entered as free text and automatically classified by an LLM pipeline, with a historical-lookup cache that gets smarter and cheaper the more you use it.

Problem

Manually categorizing personal financial transactions was slow and inconsistent, and no existing tool offered intelligent, free-text entry tailored to real spending patterns rather than rigid bank-import categories.

Approach

A cascading classification pipeline — a fast historical lookup cache checked first, falling back to an LLM with strict JSON Schema outputs only when genuinely needed. Thousands of historical transactions were backfilled using a two-phase taxonomy-discovery-then-locked-classification process to keep category naming consistent.

Result

A ledger where classification gets both cheaper and more consistent the more it's used — live-entry AI cost runs at a few paisa per transaction, with the cache absorbing most repeat patterns.

FastAPI SQLAlchemy Azure SQL Azure OpenAI Azure Key Vault Vercel

Contact

Open to discussing AI engineering roles, freelance builds, or just talking shop about GenAI in production.

sajjad@aqlen.co.uk