Backend systems built for scale, security & silence
Backend Software Engineer
Senior-minded backend engineer specialising in NestJS and Spring Boot microservices. I design multi-tenant SaaS platforms, harden APIs against real attack surfaces, and tune PostgreSQL until the query plans stop hurting.
- NestJS
- TypeScript
- Java · Spring Boot
- Microservices
- PostgreSQL
- Docker
- Redis
- NATS
Dhaka, Bangladesh · Open to remotezaagsys.com
Zawad Zamil
Backend Software Engineer
4+
years in production
Core technologies: NestJS, TypeScript, Spring Boot, PostgreSQL, Redis, Docker, NATS, Microservices, TypeORM, Socket.io, Nginx, CI/CD.
About
Backend engineer, four years in production systems
I build the half of the product nobody sees: multi-tenant APIs, event-driven services, and the database work that keeps them fast under load. NestJS and TypeScript today, Java and Spring Boot before that, PostgreSQL underneath all of it.
I am a backend engineer based in Dhaka, four years into shipping systems that other people depend on. I started on PHP and Laravel internal tools, moved to Java and Spring Boot for product work, and now spend my days in NestJS building enterprise services.
At Zaag Systems I work across three products: a multi-tenant RAG platform, an AI automation ecosystem for a top-10 global printing company, and a real-time dispatch backend serving mobile apps in Saudi Arabia. On the printing ecosystem I led the transition from a proof-of-concept monolith to five independently deployable services communicating over NATS behind a Kong gateway.
The work I am best at is the work where being right matters more than being novel: tenancy boundaries that hold, transactions that do not leave partial state, consumers that survive a redelivery, and query plans that stop hurting. I am open to remote backend roles and select contracts.
At a glance
- Experience
- 4+ years, backend-focused
- Currently
- Software Engineer · Zaag Systems Ltd
- Based in
- Dhaka, Bangladesh · UTC+6 · remote
- Domains
- Multi-tenant SaaS · AI platforms · Real-time · Commerce
- Availability
- Open to select contracts
- records orchestrated
- 1M+records orchestratedTCC Reader ingestion feeding downstream AI processing
- services designed
- 5services designedPOC monolith split into an event-driven ecosystem on NATS
- faster API responses
- 25%faster API responsesIndexing and query optimisation on high-volume paths
- fewer environment bugs
- 20%fewer environment bugsStandardised Docker development environments across the team
Experience
Oct 2024 — Present
Software Engineer · Zaag Systems Ltd
Dhaka, Bangladesh
Enterprise backend services across three products: the Toppan microservices ecosystem, the ZAAG AI multi-tenant RAG platform, and the Dr. Wash dispatch platform.
- Led the transition of a POC monolith into a production microservices ecosystem, designing five core services: Auth, Activity, Email, Job, and TCC Reader
- Built the TCC Reader service to ingest and orchestrate over 1M external records for downstream AI processing
- Implemented event-driven communication over NATS so services decouple and scale independently
- Architected multi-tenant NestJS infrastructure with RBAC and organisation-level data isolation for ZAAG AI
- Resolved N+1 query issues on high-volume data paths, cutting database overhead and latency
- NestJS
- TypeScript
- Kong API Gateway
- NATS
- PostgreSQL
- Redis
- Docker
Sep 2022 — Sep 2024
Junior Software Engineer · Zaag Systems Ltd
Dhaka, Bangladesh
Started on PHP/Laravel internal business applications, then moved to Java and Spring Boot for product work.
- Developed and maintained RESTful APIs in Laravel (Eloquent ORM, service container, MVC) with MySQL for internal business applications
- Built a complete Restaurant Management System and POS in Spring Boot, covering accounting, inventory management, and QR-code ordering
- Integrated Uber Direct and DoorDash to automate order fulfilment and real-time delivery tracking
- Implemented WebSockets for live order tracking and kitchen notifications, synchronising front- and back-of-house operations
- Improved API response times by 25% through indexing and query optimisation, and standardised Docker development environments, cutting environment-related production bugs by 20%
- Java
- Spring Boot
- PHP
- Laravel
- MySQL
- WebSockets
- Docker
Feb 2022 — Aug 2022
Embedded Software Engineer · Baraka Techsol
Canada · Remote
Backend contributions alongside embedded monitoring hardware deployed to production environments.
- Contributed to a PHP/Laravel backend across 3+ projects, integrating third-party APIs to extend application functionality
- Built and deployed ESP32/Arduino-based monitoring solutions in multiple production environments
- PHP
- Laravel
- MySQL
- ESP32 / Arduino
- REST APIs
How I build
Boundaries before code
If a layer's responsibility is blurry, the code will be too. I decide what the controller, service, and repository each own before writing any of them.
Migrations, never synchronize
Schema changes are versioned, reviewed, and reversible. Production has never auto-synced an entity in anything I have shipped.
Reuse the primitive that exists
If the project already has a guard, pipe, or interceptor, I extend it. A second way to do the same thing is a maintenance bill someone else pays.
Boring deploys
Reproducible container builds and logs you can actually grep beat clever infrastructure at 3am, every time.
Projects
Shipped, live, and carrying real traffic
Every project below is in production. Open any card for the architecture decisions behind it.
Toppan Microservices Ecosystem
POC monolith → five-service production ecosystem on NestJS & NATS
- NestJS
- TypeScript
- Microservices
- Kong API Gateway
- NATS
- PostgreSQL
Dr. Wash
On-demand car wash platform — real-time dispatch engine
- NestJS
- TypeScript
- Socket.io
- PostgreSQL
- PostGIS
- Geo-hash
CitizenPrep
Full-stack citizenship exam preparation platform
- NestJS
- TypeScript
- PostgreSQL
- React
- Tailwind CSS
- Stripe
Northern Handicraft
E-commerce platform for handcrafted goods
- Node.js
- PostgreSQL
- REST API
- Payments
- Docker
- E-commerce
Stack
The tools, and how deep I go with each
Core means daily and production-proven. Strong means shipped and comfortable. Working means I am productive with it but would not call myself the expert in the room.
NestJS
Backend
CoreTypeScript
Backend
CoreNode.js
Backend
CoreJava
Backend
StrongSpring Boot
Backend
StrongMicroservices
Backend
StrongREST & OpenAPI
Backend
CoreJWT & Passport.js
Backend
CoreNATS Messaging
Backend
StrongWebSockets / Socket.io
Backend
StrongKong API Gateway
Backend
StrongPostgreSQL
Databases & Caching
CoreTypeORM
Databases & Caching
CorePrisma
Databases & Caching
StrongRedis
Databases & Caching
CoreMongoDB
Databases & Caching
WorkingPostGIS
Databases & Caching
StrongMySQL
Databases & Caching
StrongQuery optimisation
Databases & Caching
StrongMigrations
Databases & Caching
CoreDocker
DevOps & Cloud
CoreDocker Compose
DevOps & Cloud
CoreCI/CD (GitHub Actions)
DevOps & Cloud
StrongNginx
DevOps & Cloud
StrongLinux
DevOps & Cloud
StrongAWS
DevOps & Cloud
WorkingKubernetes
DevOps & Cloud
WorkingObservability & logging
DevOps & Cloud
StrongRAG architecture
AI & Data Services
CoreAI ingestion pipelines
AI & Data Services
StrongLLM API integration
AI & Data Services
CoreVector search
AI & Data Services
Strongn8n automation
AI & Data Services
StrongAI coding agents
AI & Data Services
Strong
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Contact
Let's build something that scales
Backend architecture, API design, a system that's buckling under growth — tell me what you're working on and I'll tell you honestly whether I'm the right fit.
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Available for select contracts
Typical reply within 24–48 hours. Dhaka, Bangladesh · Open to remote.