Backend & AI Engineer · Delhi NCR, India

Building systemsthat think.

I'm Kartikey — I build the infrastructure behind agentic AI: model routers and RAG pipelines, MCP tool-use over real business systems, and multi-tenant backends that hold up in production.

View workRésumé
Kartikey Sangal
5M
Users supported
<500ms
First-token latency
10k+
Records per run
<3%
Email bounce rate
Scroll

Currently

Software Engineer at Manrke

May 2026 — Present · Remote

  • Building Calcul8, a Python microservices system that processes inbound email through OCR and LLM extraction into QuickBooks Online.
  • Led an AWS infrastructure security audit across 2 VPCs, remediating public database exposure and ECS sprawl, and migrated PostgreSQL connections to psycopg3 pooling.
  • Implemented Fernet-based OAuth token encryption at rest and drove SOC 2 critical-findings remediation across the platform.
  • 01

    Agentic AI systems

    Provider-agnostic model routing, RAG ingestion with pgvector, and MCP tool-use wired into the systems teams already work in.

  • 02

    Backend architecture

    NestJS and FastAPI services designed for scale — modular boundaries, queues, caching, and multi-tenant isolation enforced at the database.

  • 03

    Cloud & security

    AWS infrastructure audits across VPCs and ECS, encrypted OAuth credentials at rest, and SOC 2 findings driven to closed.

Experience

Where I’ve worked

May 2026 — Present

Manrke

Software Engineer

Remote

  • Building Calcul8, a Python microservices system that processes inbound email through OCR and LLM extraction into QuickBooks Online.
  • Led an AWS infrastructure security audit across 2 VPCs, remediating public database exposure and ECS sprawl, and migrated PostgreSQL connections to psycopg3 pooling.
  • Implemented Fernet-based OAuth token encryption at rest and drove SOC 2 critical-findings remediation across the platform.
PythonAWSPostgreSQLOCR / LLM

Dec 2025 — May 2026

Rwazi

Full-Stack Developer

US · Remote

  • Built the marketing and product website for Altilos, a product of Rwazi, from the ground up — shipping 8+ pages with responsive layouts.
  • Integrated Stripe for tier-based subscription pricing across 3 plans, including checkout flows and webhook-driven billing.
Next.jsTypeScriptStripeTailwind CSS

Feb 2025 — Dec 2025

The Ladder AI

Full-Stack Engineer

Remote

  • Built scalable backend systems for an app and web LMS using NestJS, with modular services and REST APIs serving both mobile and web clients, supporting up to 5M users.
  • Shipped 10+ production features end to end, from requirement gathering and API contract design through to deployment.
NestJSREST APIsNode.jsPostgreSQL

Sep 2024 — Jan 2025

Hotinbox.ai

Software Engineer

US · Remote

  • Automated scraping pipelines processing 10k+ records per run to extract targeted prospect data for outbound email campaigns.
  • Built data enrichment pipelines enabling bulk outreach to ICPs with validated contacts, improving deliverability via email verification to under a 3% bounce rate.
PlaywrightNode.jsData enrichmentEmail verification

Jan 2024 — Aug 2024

Jurix AI

Full-Stack Engineer

Remote

  • Joined an AI-based legal startup as the initial developer, architecting the complete frontend and backend for the first version of the client-facing SaaS product.
  • Integrated AI models and legal data APIs for intelligent case-law search and document analysis.
ReactNode.jsAI/LLM APIsMongoDB

Nov 2022 — May 2026

Dr. A.P.J. Abdul Kalam Technical University, Lucknow

B.Tech, Computer Science Engineering

  • GPA 7.8 / 10

Selected work

Things I’ve built

Five projects taken end to end — data model, backend architecture, AI systems and interface. Numbers below are measured in production, not estimated.

012026

CIOS

Agentic AI workspace with MCP tool-use

Client Intelligence Operating System — leading backend architecture across a 5-engineer team, owning the NestJS Gateway, Skills system and Artifact generation. A provider-agnostic model router (Anthropic, OpenAI, Gemini) with BYOK and SSE streaming, plus RAG ingestion with SHA-256 dedup and MCP tool-use over ClickUp, Drive, Slack and Gmail with multi-tenant isolation via PostgreSQL RLS.

<500ms
first token
5
engineers led
3
model providers
NestJSFastAPIpgvectorRedisMCPPostgreSQL
Private · client work
022026

Blue Nelumbo

CFA exam prep platform, full stack delivered solo

The complete technical stack for a CFA exam prep startup, supporting all 3 levels of certification. A modular NestJS API with Prisma and Redis caching across 15+ endpoints, serving a Next.js web app and a React Native mobile client on AWS Lambda, with Razorpay billing and DRM-based content protection.

3
CFA levels
15+
endpoints
2
clients shipped
NestJSNext.jsPrismaReact NativeAWS LambdaRazorpay
Live ↗
032025

LadderFlow

Voice-first content generation for creators

A voice-first SaaS platform that turns a single interview into multi-platform content. Deepgram Voice Agent runs the interview in real time at sub-200ms latency; GPT-4o transforms the transcript into LinkedIn, Twitter and newsletter posts, with trend discovery automated through N8N.

<200ms
voice latency
3
output platforms
Next.jsTypeScriptDeepgramGPT-4oFastAPIN8N
Live ↗Source ↗
042025

CrMint

Full-stack CRM with pub-sub campaign delivery

A CRM platform for personalized campaign delivery. Publisher-subscriber architecture handles 100+ API calls per second with zero downtime; Redis streams ingest 500+ customer interactions a minute. 99.9% uptime in production.

100+
calls/sec
99.9%
uptime
500+
events/min
Node.jsRedisReactGroq LLMMongoDBOAuth
Live ↗Source ↗
052025

Time2Qualify

AI assessment recommender on vector search

Recommendation engine that reads a job description and surfaces the top 10 candidate assessments. 150+ SHL assessments embedded with HuggingFace and served from Pinecone with decimal relevance scoring.

150+
vectors indexed
top 10
ranked matches
Node.jsExpressPineconeHuggingFaceMongoDBJWT
Source ↗

Toolkit

The stack I reach for

AI / ML

6
  • RAG Pipelines
  • MCP
  • Agent Orchestration
  • LLM Routing
  • Vector Search
  • pgvector

AI Dev Tools

5
  • Claude Code
  • Codex
  • Cursor
  • GitHub Copilot
  • Windsurf

Languages

5
  • TypeScript
  • Python
  • JavaScript
  • SQL
  • C/C++

Frameworks

6
  • NestJS
  • FastAPI
  • Next.js
  • React
  • React Native
  • Express

Databases

6
  • PostgreSQL
  • pgvector
  • MongoDB
  • Redis
  • Pinecone
  • MySQL

Tooling

6
  • Docker
  • AWS
  • Nginx
  • Prisma
  • BullMQ
  • Git

250+

DSA problems solved

LeetCode, GFG

1600+

LeetCode rating

Contest rated

Merged

GSSoC contribution

MediaRecorder PR → Placify

PCAP

Cisco certified

Python + CCNA introduction

Certified

5

Contact

Let's build something.

I'm open to interesting problems in backend and applied AI — and to freelance work worth doing. The fastest way to reach me is email.

Upwork Rising Talent — 5.0 rating across completed freelance projects in payment systems and infrastructure migration.

or email directly
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