Shahriar Rahman Rubayet
Software Engineer II at GoZayaan · Dhaka, Bangladesh

Shahriar Rahman Rubayet

I build backend systems that millions depend on.

Backend engineer working in Go, Python and Node.js on payment rails, courier logistics and flight search. Three years shipping services that move real money and real parcels — for fintech at national scale, and now for travel.

Portrait of Shahriar Rahman Rubayet
3+ yrsBackend engineering
25M+Users served
25M+ Users reached by systems I've shipped
200+ Production APIs designed and delivered
1M+ Events processed per day via Kafka
50% Latency cut through Redis cache design
Experience

Where I've built things

From an EdTech internship to national payment rails to flight search — each step traded up in traffic, in money moved, and in how much of the system was mine to own.

Software Engineer II

GoZayaan Limited Dhaka, Bangladesh

Nov 2025 — Present
  • Integrated international flight providers into the flight-search service that drives 40% of the company's total revenue, built on Go, PostgreSQL, GCP, Django and Node.js.
  • Stood up CI/CD for the new flight-search platform with GitHub Actions and ArgoCD, and instrumented it with Prometheus and Grafana so regressions surface before users feel them.
GoPostgreSQLGCP DjangoNode.jsArgoCD GitHub ActionsPrometheusGrafana

Software Engineer

TechnoNext Limited Dhaka, Bangladesh

Jan 2025 — Nov 2025
  • Developed 200+ APIs for a courier service using Python, Node.js, Go, Redis, PostgreSQL and Kong — generating 60M BDT in monthly revenue and delivering 50k parcels a day.
  • Built a proxy server for two leading airlines in Go, Node.js, MongoDB and Redis, structured around Domain-Driven Architecture for maintainability and scale.
  • Designed asynchronous order processing on queue patterns with AsynQ in Go, sustaining 200 rps of delivery traffic.
  • Authored gRPC handlers for order creation, OTP verification and invoice generation, wired to AWS SES, Resend and RouteMobile.
  • Created a Windows printing service on CUPS (lp, lp-stat) handling custom paper sizes, margins and label printing — now in daily use across 50 operational hubs.
  • Automated database migrations and schema evolution across 15M+ legacy records in PostgreSQL, keeping deployments uneventful.
GoPythonNode.js gRPCPostgreSQLMongoDB RedisKongAsynQ AWS SESCUPSDDD

Software Engineer

Upay — UCB Fintech Limited Dhaka, Bangladesh

Oct 2023 — Dec 2024
  • Built high-performance backend systems that processed secure payments and data transactions for 25M+ users.
  • Shipped the APIs behind Upay Spin the Wheel, a product with 3M+ users nationwide, in Go, Python, PostgreSQL, Django REST Framework and Redis.
  • Delivered Asian Network, Circle Network and Antaranga — three internet bill payment services with 300K+ active users.
  • Engineered payment service APIs for Uddipan, a microfinance NGO with 1.2M+ active clients.
  • Integrated payment APIs for BPDB, BREB, DESCO and Dhaka WASA into the USSD service, serving 150K+ active users.
  • Designed and deployed an event-driven architecture on Python, Apache Kafka and Zookeeper, processing 1M+ messages per day.
  • Optimised Redis as a distributed cache and session store — 50% lower latency, materially less database load, and consistency held.
  • Wrote payment automation APIs in Go that cut the service operations team's manual workload by 70%.
GoPythonDjango REST PostgreSQLRedisApache Kafka ZookeeperUSSDEvent-Driven

Software Engineering Intern

DreamOnline Limited Dhaka, Bangladesh

Feb 2023 — Sep 2023
  • Built a web push notification system with Next.js and Firebase Cloud Messaging, lifting engagement on an EdTech platform with 30K+ active users.
  • Developed the platform's admin panel in Node.js, Express and MongoDB, supporting 1,000+ schools.
Next.jsNode.jsExpress MongoDBFirebase FCM
Selected work

Systems, not side projects

Everything below runs in production and has real users behind it. The numbers are the point — they're the reason the work mattered.

01 GoZayaan

International Flight Search

Provider integrations behind the flight-search service — normalising fares, availability and booking flows from multiple international suppliers into one consistent API surface.

40%of company revenue
Multiprovider integration
GoPostgreSQLGCPDjango
02 TechnoNext

Courier Delivery Platform

200+ APIs covering order intake, routing, hub operations and settlement — with asynchronous processing on AsynQ queues so peak load degrades gracefully instead of dropping parcels.

60M BDTrevenue / month
50kparcels / day
200 rpssustained
GoPythonNode.js KongRedisPostgreSQL
03 TechnoNext

Airline Proxy Server

A domain-driven proxy layer fronting two leading airlines — isolating carrier quirks behind a stable internal contract, with Redis-backed caching for hot lookups.

2major carriers
DDDarchitecture
GoNode.jsMongoDBRedis
04 Upay

Spin the Wheel

Reward-campaign APIs for a nationwide fintech promotion — idempotent prize allocation, Redis-guarded fairness, and enough headroom to survive campaign-launch traffic spikes.

3M+users nationwide
GoPythonDjango RESTRedis
05 Upay

Utility Payments over USSD

Payment integrations for BPDB, BREB, DESCO and Dhaka WASA delivered through USSD — reaching users on feature phones, where reliability matters more than anything else.

150K+active users
4national utilities
GoPostgreSQLUSSD
06 Upay

Event-Driven Payment Pipeline

Kafka-based architecture decoupling payment ingestion from downstream settlement, notification and reconciliation — replacing synchronous chains that failed together.

1M+messages / day
50%latency reduction
PythonApache Kafka ZookeeperRedis
Toolkit

What I work with

Go and Python are home. Everything else is chosen per problem — and I've shipped production code in all of it.

Languages

GoPythonJavaScript C++SQL

Backend & APIs

gRPCRESTDjango REST FastAPIFlaskNode.js ExpressKong Gateway

Data & Messaging

PostgreSQLMySQLMongoDB RedisApache KafkaZookeeper AsynQ

Cloud & DevOps

GCPAWSDocker KubernetesArgoCDGitHub Actions PrometheusGrafana

Frontend

ReactNext.js Firebase FCM

Practices

Event-Driven ArchitectureDomain-Driven Design Async Queue PatternsSchema Migration Unit TestingCI/CDObservability
About

A little more context

I'm a backend engineer based in Dhaka, Bangladesh. Most of my work has lived in places where failure is expensive — payment rails, courier logistics, flight bookings — so I've developed a strong bias toward systems that behave predictably under load and are honest about what they're doing.

At Upay I spent a year on national fintech infrastructure: utility payments over USSD, microfinance disbursement, a Kafka pipeline moving a million messages a day. At TechnoNext I built a courier platform from the API layer down to the label printers running in 50 hubs. Now at GoZayaan I work on flight search — supplier integrations, plus the CI/CD and observability that keep the platform shippable.

What I care about: clear domain boundaries, queues instead of tight coupling, caches you can reason about, and migrations that don't wake anyone up at 3am. What I'm still getting better at: Kubernetes internals, and writing the kind of tests that catch things staging doesn't.

Open to interesting backend and distributed-systems work. Easiest ways to reach me are email or LinkedIn.

“What I cannot create, I do not understand.”

— Richard Feynman
Contact

Got something worth building?

I'm always up for a conversation about backend architecture, payment systems, or a role where the hard part is the system rather than the framework.