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Full Stack Engineer

SYEDABDULAZIZ

Production web apps, APIs & backends. Applied AI where it makes the system genuinely more useful. US, Canada & global clients.

Full Stack Engineer · Cuthours · 2023 – Present · 3+ years production delivery

ResumeContact

Core production stack

TypeScriptReactNext.jsNode.jsPostgreSQLMongoDBAWSPythonTailwind

9+ client projects shipped · remote US, Canada & global

My Expertise

Three production lanes — backend and cloud, frontend and product UI, and measured AI — backed by case studies on this site, not buzzwords.

Backend
& cloud

Node.js APIs, data layers, and AWS-backed services — designed for production traffic, clear contracts, and operable deploys.

  • REST services in Node.js with validation at the boundary, consistent error shapes, and auth enforced on the server — not delegated to the client.
  • MongoDB and PostgreSQL in production: schemas, indexes, and query paths aligned with triage lists, reporting, and concurrent writes.
  • AWS where the product uses it — Bedrock, Aurora/RDS, DynamoDB, S3, Textract — with infrastructure choices tied to observability and rollback.
  • Split deploy when the workload needs it: UI on Vercel, APIs on Railway or containers, Docker Compose locally, and CI gates before merge.
Node.jsExpressRESTMongoDBPostgreSQLAWSDockerRailway

Evidence on this site

  • Link Health — enrollment APIs on Aurora/DynamoDB; Bedrock chat in the live stack
  • PR Card Renewal — case state machine, upload validation, admin triage APIs
  • ContextIQ — Python Starlette API on Railway; hybrid retrieval and eval pipeline

Frontend
& product UI

React and Next.js applications that staff and customers use daily — wired to live APIs, not mock data.

  • Production UIs in React and Next.js with TypeScript: multi-step wizards, admin consoles, filters on large datasets, and role-scoped views.
  • State and structure sized for maintenance — shared patterns where they reduce drift, without abstraction for its own sake.
  • Tailwind for consistent layout; focus stays on correct behavior under real data, accessible controls, and stable performance.
  • Mobile surfaces (React Native) appear in project work such as Hostel Den — same API contracts as web, documented in case studies only.
ReactNext.jsTypeScriptTailwind CSSApp Router

Evidence on this site

  • BNBComps — interactive comps tables, debounced search, cache-friendly payloads
  • PR Card Renewal — applicant wizard and caseworker triage console
  • ContextIQ — chat, eval dashboard, failure browser, and architecture views

AI
systems

Measured RAG, LLM API integration, and agent-style orchestration — eval gates and refusal before demo chatbots.

  • Eval-first RAG: golden suites, hybrid dense+sparse retrieval, citations, refusal when context is weak, and CI so retrieval cannot regress silently.
  • LLM APIs — OpenAI API and compatible providers — with streaming, grounding, token caps, rate limits, and cost visibility.
  • Agent-style flows when the product needs tool calls or multi-step reasoning — not a vector index with a chat widget on top.
  • Honest scope: faithfulness and refusal metrics are tied to the generator and suite documented in each case study.
RAGAI agentsOpenAI APIHybrid retrievalEval / CISSE

Evidence on this site

  • ContextIQ — 89.3% recall, 100% faithfulness, 100% refusal accuracy (75-query suite); Vercel + Railway
  • Portfolio assistant — Gemini streaming Q&A grounded in site data; origin check and rate limits
  • Link Health — Bedrock chat (Leo) beside enrollment; personal Leo ownership not claimed here

How AI shows up in the work

Applied AI

Three implementations at different depths — an owned RAG platform, this site's grounded assistant, and AI inside a live civic product. Each has a case study or live surface you can inspect.

Owned · eval-first RAG platform

ContextIQ

Open-source RAG I designed and shipped end to end — not a notebook demo. Hybrid retrieval, cited answers, explicit refusal, trace and eval dashboards, and a GitHub Actions gate so chunking or retrieval changes cannot merge without measured proof.

  • Ingest → chunk → embed (BGE-small) → dense + BM25 → RRF → rerank → cite or refuse.
  • Dense-only recall@5 was 3.9% on the golden set; hybrid + rerank reached 89.3% context recall on the same answerable queries.
  • Product UI on Vercel; Python Starlette SSE API on Railway; Docker Compose for local full stack.
  • OpenAI-compatible and local (Ollama) generation paths; optional Bedrock Haiku with cost surfaced in UI.
Context recall
89.3%
Faithfulness
100%
Refusal accuracy
100%
Hallucination
0%
  • Next.js · Vercel
  • Python · Railway
  • Hybrid RAG · RRF
  • OpenAI API
  • GitHub Actions eval

Faithfulness 100% is on the documented extractive path; context precision 41.6% remains the open lever — stated in the case study.

Built on this site · owned end to end

Portfolio AI assistant

A production LLM feature embedded in this portfolio: streaming answers grounded in the same profile and case-study data visitors can read on the site — plus the API route and abuse controls around it.

  • Vercel AI SDK + Gemini 2.5 Flash over POST /api/chat with streamed responses.
  • System prompt built from live profile and public projects — not a generic persona.
  • Fails closed: origin check, per-IP rate limit, Zod validation, token and history clamps.
  • Not an agent product — no tool calling; hiring facts should still go through email.
  • Vercel AI SDK
  • Gemini 2.5 Flash
  • Streaming SSE
  • POST /api/chat

Production safeguards

  • Origin check on browser POSTs
  • Per-IP rate limit
  • Message count and character clamps
  • Output token cap (700)
  • Zod request validation
  • Unavailable-provider fallback → email CTA
  • Generic API errors — no stack traces to clients
  • Accessible dialog, Escape to close
  • On-page disclaimer: answers may be imperfect

Client platform · AI in production

Link Health

Massachusetts benefits enrollment at scale: applicants and Patient Navigators share one domain for SNAP, WIC, Lifeline, MSP, and related programs. AI shows up as Bedrock chat (Leo) beside forms, OCR, eligibility logic, and a staff CRM — applied inside a real civic platform.

  • Public chat and case management on one AWS-backed model — not a standalone widget.
  • Stack includes React, Hono, Aurora PostgreSQL, DynamoDB, S3, Textract, and Bedrock.
  • Document processing and eligibility workflows share the same persistence layer as staff tools.
  • Live at link-health.org; full architecture and tradeoffs are in the case study.
  • AWS Bedrock
  • React
  • Hono
  • Aurora
  • DynamoDB
  • OCR

Bedrock/Leo is in the deployed product. My exact ownership of prompts, knowledge bases, guardrails, and evaluation is unconfirmed — that scope is not claimed on this site.

Engineering around the model

Shared patterns across ContextIQ and this site's assistant — validation before inference, explicit limits, and honest failure modes. Details vary by product; nothing here is claimed without implementation.

  • Model selection

    Gemini 2.5 Flash for short, grounded Q&A — latency and cost over a larger chat model.

  • Prompt / context

    System prompt is built from the live profile and public case studies, not a free-form persona.

  • Validation

    Request body is schema-checked. Invalid JSON and oversized histories are rejected before a model call.

  • Abuse prevention

    Trusted origin, sliding-window rate limit, clamped parts, and prompt instructions that ignore jailbreaks.

  • Cost control

    Flash model, 24-message window, 2,000-character parts, max 700 output tokens.

  • Fallback

    If the Gemini key is missing, /api/status reports chat offline and the UI points to email instead of failing silently.

  • Error handling

    Provider, timeout, rate-limit, empty, and network failures map to short visitor-facing copy. Server logs stay on the server.

  • Privacy

    Conversation is not written to a database in this app. It lives in the browser session and the request to the model.

  • Human oversight

    Hiring and facts that matter should go through email. The assistant is a convenience layer, not a source of record.

Client work

Selected Projects

8 case studies — civic tech, enterprise, e-commerce, and automation. Some work stays NDA or off the public web.

Link Health Massachusetts benefits enrollment — programs and Chat with LEO
Featured
Platform / Civic TechLive

Link Health

Benefits enrollment: public chat + clinic case management on one AWS domain.

ReactTypeScriptHonoAWSPostgreSQLDynamoDB

More work

Applied AI / RAGLive

ContextIQ

Eval-first RAG for production knowledge systems: hybrid retrieval, citations, refusal, and a CI quality gate.

Next.jsPythonStarletteSSE
Web DevelopmentLive

PR Card Renewal Platform

PR card renewal with validated uploads, shared case state, and a staff triage queue.

ReactNode.jsMongoDBTailwind
EnterprisePrivate project

Birch Gold Employee Dashboard

Internal HR/ops dashboard: RBAC, indexed Postgres reports, CSV exports.

ReactNode.jsPostgreSQLREST API

Experience

Production roles

Where I owned web apps, APIs, and data for international teams — same dates and scope as the resume.

Full Stack Engineer @ Cuthours

Lahore, Pakistan2023 – Present
cuthours.com
  • Own end-to-end delivery for booking and operations products: Node.js REST APIs, MongoDB data access, and production React/Next clients.
  • Focus on clear API contracts, auth boundaries, and correct behavior under concurrent use.
  • Extend the same domain to React Native where iOS/Android staff or guest flows share APIs with web.

Stack in this role

TypeScriptReactNext.jsNode.jsREST APIsMongoDBPostgreSQLReact NativeTailwind CSSAWSRAGOpenAI API

Selected Work

Projects