Available for senior backend rolesAdelaide, Australia

Senior software engineer building scalable fintech & payment systems.

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Signal clear·Shipping since 2019

Years engineering

800+

Brands on Vezmo

200M+

Catalogue scale

IEEE publications

About

Money moves through code I write — so I write it like it's load-bearing.

I'm a senior backend engineer who builds the load-bearing parts of fintech and SaaS products. Seven years of shipping Node.js and TypeScript services into regulated environments — Central Bank-licensed payment operators, Buy Now Pay Later platforms with AI-driven credit decisioning, and finance SaaS serving hundreds of brands worldwide. I lead the work end to end: architecture, APIs, security, observability, and the unglamorous reliability details that quietly decide whether a system survives its first real scale event.

01
Architect for change
Bounded contexts, versioned contracts, and reversible decisions. Systems should be safe to evolve, not just safe to ship.
01
Boring where it matters
Postgres, queues, idempotent APIs, observable releases. Novelty belongs in product, not in the load-bearing parts of the stack.
01
Production is the spec
Contracts, audit trails, and rollback paths are designed in. If it can't be observed and rolled back, it isn't done.

Toolkit

Tools I trust in production.

Backend

Node.js
NestJS
Express.js
TypeScript
REST APIs
GraphQL
Microservices
Event-driven

Frontend

React
Redux
TypeScript
Next.js
HTML5
CSS3
Tailwind

Cloud & DevOps

AWS
DigitalOcean
Docker
GitHub Actions
GitLab CI
Linux
Zero-downtime deploys

Databases

PostgreSQL
MySQL
MongoDB
Redis

Security

OAuth2 / JWT
OWASP Top 10
Rate limiting
Secrets management
RBAC
Audit logging

Practices

Agile / Scrum
Domain-driven design
Clean architecture
Code review
Performance tuning
Observability

Experience

Seven years shipping production systems — from monoliths to microservices.

Dec 2023 — Present
Remote · Malaysia
Senior Software Engineer
Moby Money Sdn Bhd
Build, maintain, and scale a Buy Now Pay Later platform serving Malaysian consumers and merchants — owning core payment, credit, and merchant-integration surfaces.
- Built KYC onboarding and identity verification pipelines integrating third-party providers, document checks, and risk signals.
- Built an AI-driven auto-limit assignment engine that infers a starting credit limit from user profile signals and credit history at onboarding — removing manual underwriting from the new-user path.
- Designed an AI-driven credit assignment engine for Increase-Limit applications — automating decisioning that previously required manual review.
- Re-architected scheduled jobs (repayment runs, late-fee accruals, statement generation) to be horizontally scalable and idempotent under retries.
- Upgraded and scaled the Pay Now and Installment payment flows — improving throughput, reducing failed transactions, and tightening reconciliation.
- Owned merchant integration: onboarding APIs, checkout SDK contracts, settlement workflows, and partner-facing webhooks.
Node.jsPHP/LaravelMySQLDockerAWSRedis
May 2023 — Nov 2023
Remote · Bangladesh
Senior Software Engineer
HelloPay Ltd.
Architected the MVP for a Payment Service Operator licence — a regulated fintech product for the Central Bank of Bangladesh.
- Built compliant KYC, ledger, and transaction services in NestJS with PostgreSQL and clear domain boundaries.
- Implemented secure authentication, RBAC, and immutable audit trails to satisfy regulator expectations.
- Owned containerised deployment on DigitalOcean with repeatable build/release/rollback workflows.
- Led a cross-functional Agile team through architecture, planning, and production rollout.
NestJSTypeScriptPostgreSQLReactDockerDigitalOcean
Jul 2021 — Apr 2023
Remote · E-commerce
Software Engineer · Lead Developer
Accept Global Ltd.
Lead developer for wholesalecart.com — winner of the South Asian Business Excellence Award 2022 for Best B2B E-Commerce Website, and at the time the country's leading dropshipping platform.
- Replatformed the business off a slow Shopify storefront onto a scalable Laravel + React stack, lifting page speed, throughput, and customisation headroom.
- Ran a phased catalogue, customer, and order migration with dual-write cutover — zero merchant downtime through the transition.
- Designed versioned REST APIs with idempotency, pagination, and rate limiting; hardened endpoints with input validation and structured error handling.
- Set up CI/CD with staging, automated smoke tests, and zero-downtime production deploys.
- Partnered with marketing and data teams on centralised logging, analytics, and reporting pipelines.
LaravelPHPReactMySQLRedisNode.js
Apr 2020 — Jun 2021
Remote · Italy
Software Engineer
Asyncus
End-to-end backend delivery for client projects — from requirements through deployment.
- Built and consumed REST APIs across React frontends with full CI/CD coverage.
- Owned architecture, deployment configuration, and automated release pipelines.
LaravelPHPMySQLReactJavaScript
Jun 2019 — Mar 2020
Remote · International
Freelance Software Developer
Fiverr Inc.
Custom backend solutions for international clients across e-commerce and business management — Node.js, Express, MongoDB, and PHP stacks.
- Managed pre-sale analysis, scoping, and client communication independently.
- Shipped production features under tight client SLAs and review cycles.
Node.jsExpressMongoDBPHP

Selected Work

6 flagship systems — shipped, scaled, and audited in production.

Case 01 — FinTech SaaS

Vezmo

Consultant & Technical Lead · 2024 — Present

Ground-up

system designed from zero to scale in production

Problem

Greenfield finance platform — no codebase, no schema, no infra — that had to scale from day one to 800+ tenants across invoicing, payments, contracts, billing, and bookkeeping without a rewrite mid-flight.

Built

Designed the architecture top-to-bottom: 6 bounded microservices on Node.js + PostgreSQL, OAuth2 public API, event bus, multi-tenant data model, observability, and CI/CD — all built to scale before the first tenant landed.

Outcome

Production system shipped from a clean sheet, scaled to 800+ brands worldwide on one regulator-grade platform with 99.9% release reliability.

Node.jsTypeScriptPostgreSQLEvent BusAWSDocker

Case 02 — Regulated BNPL

Moby BNPL Platform

Senior Software Engineer · 2023 — Present

0→AI

manual underwriting replaced with AI credit decisioning

Problem

Every BNPL signup needed manual underwriting; Pay Now and installment jobs missed SLAs as volume grew, and limit-increase requests waited days for human review — blocking merchant GMV.

Built

AI-driven credit decisioning at onboarding and limit-increase, KYC pipeline, and horizontally scalable, idempotent repayment / late-fee / statement jobs across the merchant integration suite.

Outcome

Manual underwriting removed from both onboarding and limit-increase paths; live merchant integrations with checkout SDK, settlement, and webhooks running in production.

Node.jsPHP/LaravelMySQLRedisAWSDocker

Case 03 — B2B E-Commerce

Wholesalecart

Lead Developer · 2021 — 2023

B2B dropshipping platform · SABE Award winner 2022

Problem

The storefront had outgrown Shopify — page-speed regressions, capped customisation, and per-transaction fees compounding on every order — but live merchants couldn't lose a single transaction during cutover.

Built

A custom Laravel + React stack with phased dual-write migration, plus end-to-end automation for procurement, order sorting, courier booking, invoicing, and merchant reports.

Outcome

Won the 2022 SABE Award for Best B2B E-Commerce Website with 0 minutes of merchant downtime through the full Shopify → custom-stack cutover.

LaravelPHPReactMySQLRedisNode.js

System Design

Patterns I reach for — proven in regulated fintech and high-traffic e-commerce.

Event-Driven Payments

Authorisation API decouples from ledger and reconciliation via durable queues. Idempotency keys + DLQs guarantee at-least-once processing without double-charging.

API Gateway

Auth Service

Queue

Ledger

Reconciler

DLQ

Microservices Boundaries

Domains split along business capability — Identity, Invoicing, Payments, Bookkeeping. Each owns its data; cross-domain workflows ride the event bus.

Identity

Invoicing

Payments

Bookkeeping

Event Bus

Scalable Read Path

Edge caching + Redis hot keys + read replicas absorb burst traffic. Cache invalidation rides the same event bus that drives ledger writes.

CDN

API

Redis

Read Replica

Primary DB

Zero-Downtime Releases

Blue/green Docker deploys behind a load balancer, with database migrations run as expand-then-contract. Health checks gate traffic shift.

Blue

Green

Migrations

Health Checks

GitHub

One year of commits.

1,941

contributions

19d

longest streak

current streak

105

peak · Tue, 16 June

@majhar-nayem↗live

JulAugSepOctNovDecJanFebMarAprMayJunJul

MonWedFri

busiest · Tue

lessmore

Education & Research

Master of Artificial Intelligence & Machine Learning

Adelaide University · Adelaide, Australia

Incoming

Aug 2026 — Expected

BSc in Computer Science & Engineering

North South University · Dhaka, Bangladesh

Apr 2016 — Dec 2020

Research

4 IEEE-indexed publications · 110+ citations. Applied ML research in predictive modelling and ensemble methods (LightGBM, XGBoost, Random Forest, SVM, K-Means).

IEEE CCWC · Las Vegas, 2023
IEEE · Singapore, 2020
IEEE · Coimbatore, 2020

Contact

Let's build something that scales.

I'm available for senior backend, platform, and staff roles — full-time or consulting. Best way to reach me is email.

majharul.nayem042@gmail.com

GitHub

Senior software engineer building scalable fintech & payment systems.

Money moves through code I write — so I write it like it's load-bearing.

Architect for change

Boring where it matters

Production is the spec

Tools I trust in production.

Seven years shipping production systems — from monoliths to microservices.