University TA Agent
Modular skill-registry / router / executor pattern with RAG-based Q&A, auto-grading, and Zod-validated tool schemas.
Available for principal / staff engineering roles
Emon Reja
Principal Engineer·NestJS / Node.js Backend·Cloud & DevOps·AI / RAG Systems
I design modular NestJS monorepos, event-driven microservices, and the multi-cloud infrastructure they run on — then ship production LLM/RAG and agentic AI pipelines on top. Based in Dhaka, Bangladesh 🇧🇩
50s→2s
Query load time
+70%
Backend throughput
−60%
Deployment time
−80%
Data-loss risk
20+
AI agents shipped
About
Nine years across backend, cloud, and AI.
I'm a Principal Engineer with 9+ years spanning NestJS/Node.js backend architecture and multi-cloud infrastructure. I build modular NestJS monorepos, async queue systems with BullMQ, and event-driven microservices — while owning the AWS/GCP infrastructure, Terraform IaC, and CI/CD pipelines they run on.
That full ownership of the delivery stack — TypeScript services, container orchestration with Docker & Kubernetes, and production LLM/RAG and agentic AI pipelines (LangChain, LangGraph, Claude & OpenAI) — lets me cut a problem at whatever layer it actually lives in.
The results speak in numbers: query load from 50s to under 2s, backend throughput up 70%, deployment time down 60%, data-loss risk down 80%, and 20+ AI agents in production.
Backend Architecture
Modular NestJS monorepos, typed providers, Zod validation, async BullMQ pipelines, and event-driven microservices.
Cloud & DevOps
AWS/GCP infrastructure, Terraform & CDK IaC, Kubernetes orchestration, CI/CD, and observability that stays green.
AI / RAG Systems
Model-agnostic RAG platforms, LangGraph agentic workflows, pgvector search, and Claude/OpenAI pipelines in production.
Experience
A track record of shipping at scale.
From backend developer to principal engineer — eight roles across Bangladesh, the US, and Canada.
Senior Software Engineer · Programming Hero
Jan 2025 — PresentDhaka, Bangladesh
- Architected NestJS microservices with modular feature modules, custom guards, and interceptors for a real-time blockchain data dashboard — slashing query load from 50s to under 2s.
- Designed async job-queue architecture with BullMQ for data-mutation pipelines, eliminating critical bottlenecks and boosting backend throughput by 70%.
- Refactored the legacy service layer into typed NestJS providers with Zod validation, achieving consistent processing under 500ms.
- Built a NestJS + LangChain scraper service with an LLM-powered RAG classification pipeline (OpenAI embeddings, pgvector).
Senior Software Engineer · ASON AI INC
Sep 2024 — PresentRemote, USA · Part-time
- Engineered a model-agnostic NestJS RAG platform supporting hot-swappable LLM and embedding backends via provider abstraction and dependency injection.
- Built a LangChain tool-suite module enabling seamless third-party integrations across multiple LLM providers for business clients.
- Implemented LangGraph agentic workflows within NestJS services, improving multi-step reasoning across 20+ deployed AI agents.
Senior DevOps Engineer · Gain Solutions
Sep 2021 — Sep 2024Dhaka, Bangladesh
- Designed and maintained AWS infrastructure (EC2, S3, VPC, IAM, RDS, Auto Scaling) for enterprise-grade, multi-region Node.js/NestJS deployments.
- Implemented Infrastructure as Code with Terraform and CloudFormation for repeatable, version-controlled provisioning across dev, staging, and prod.
- Built CI/CD pipelines with Jenkins and GitHub Actions, reducing deployment time by 60% and eliminating manual release steps.
- Containerized microservices with Docker and orchestrated workloads on Kubernetes for high availability and horizontal scalability.
- Configured monitoring with Prometheus, Grafana, and ELK; enforced IAM least-privilege, VPC segmentation, and encrypted S3 — reducing data-loss risk by 80%.
AWS CDK Developer · Omidnetcare
Jul 2022 — Dec 2022Philadelphia, USA · Remote
- Authored Infrastructure as Code with AWS CDK (TypeScript) to provision scalable, compliant cloud environments for Node.js/NestJS services.
- Built and maintained Jenkins CI/CD pipelines; implemented Auto Scaling and S3 backup automation.
Backend Developer · Ezcorps
Oct 2019 — Oct 2021Toronto, Canada · Remote
- Built GraphQL APIs in Node.js enabling interoperability across services and front-end apps; migrated core services to NestJS architecture on a highly available AWS backend.
Senior Backend Engineer · Console IT
Apr 2018 — Oct 2021Sylhet, Bangladesh
- Constructed RESTful APIs and maintained backend services; automated deployment pipelines with Bash and Linux administration, cutting deployment time by 50%.
Backend Developer · CRUX
Jun 2016 — Apr 2019Dhaka, Bangladesh
- Built scalable AWS-backed infrastructure and collaborated with front-end teams for seamless system integration.
Selected Work
Key projects.
Production systems where backend architecture, cloud infrastructure, and applied AI meet.
Async Video Analysis Pipeline
NestJS worker on AWS ECS Fargate + SQS with Claude Batch API — multimodal RAG using Whisper transcription and Gemini embeddings.
Research Agent
GPT-4 research platform with MongoDB Atlas, PDF export, query classification, and external search routing.
Hello Doorstep
Serverless microservice platform — full IaC-driven deployment on AWS Lambda with DynamoDB, Cognito, S3, SES, and SQS.
Alti Assistant
Multi-service AI assistant on GCP with Docker — LLMs, vector search, agentic tool integrations, and Cloud Run CI/CD.
Taskco
Multi-tenant SaaS — NestJS API, Next.js frontend, Docker, Kubernetes, Nginx — full CI/CD and containerized deployment.
Toolbox
Skills & technologies.
The stack I reach for across backend, infrastructure, and AI.
Primary Stack
NestJSNode.jsTypeScriptExpress.jsPythonPHP (Laravel)
AI / ML
LangChainLangGraphClaude APIOpenAI APIRAGpgvectorVector SearchAgentic AIPrompt Engineering
Cloud & IaC
AWSEC2LambdaDynamoDBECS FargateCDKCloudFormationCognitoGCPDigitalOceanTerraform
CI/CD & Automation
GitHub ActionsJenkinsGitLab CIBashPython Automation
Containers & Infra
DockerKubernetesNginxMicroservicesLinux Admin
Monitoring
PrometheusGrafanaELK StackCloudWatchLog Aggregation
Databases
PostgreSQLMongoDBRedisDynamoDBMySQLAdvanced SQL
Architecture & APIs
Event-DrivenAsync Queues (BullMQ)Multi-tenant SaaSRESTGraphQLWebSocketsgRPC
Background
Education & languages.
B.Sc. — Computer Science & Engineering
Metropolitan University, Sylhet, Bangladesh
Languages
Contact
Let's build something reliable.
Open to principal and staff engineering roles in backend, cloud, and applied AI — remote or Dhaka-based. The fastest way to reach me is email.