Open to senior IC roles

Backend systems,
drawn to spec.

SENIOR BACKEND ENGINEER · 10+ YEARS

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About me

Who I am and what I have shipped.

Gilang Ramadan

Ten years building fintech-grade marketplace and payment platforms on Ruby on Rails, Go, and PostgreSQL. My core expertise is backend systems. I have delivered projects for one of the largest FMCG manufacturers in Indonesia, for startups, and for international companies. Most recently, I helped take an early-stage rental and services marketplace from zero to launch. Now focused on hands-on senior IC work with distributed teams.

1,000 TPS

at 99.9% uptime through peak utility payment cycles

Weyland · fintech super-app · 2017–2019

181,000+

transactions a month, IDR 8.6B monthly volume, within two years of launch

Weyland · fintech super-app · 2017–2019

154,000

monthly transactions at a 92% delivery success rate

AtozGo · food delivery · 2019–2022

1,000+

concurrent WebSocket connections on AnyCable, under test

Virtual Spirit · marketplace · 2022–2026

Each figure is taken from the experience log.

Tech stack

Parts list: the tooling these systems are actually built on.

cloud

Infrastructure

Docker / Docker ComposeKubernetesTerraform (IaC)AWS / GCPNginx / Traefik
code

Languages

Ruby / RailsGoNode.js / NestJSPHP / LaravelJavaScript
database

Data storage

PostgreSQLMySQL / SQL ServerRedis / MemcachedMongoDBPrisma / ActiveRecord
speed

Performance

Prometheus / GrafanaDistributed tracingLoad balancingQuery & index tuningBullMQ / Sidekiq
Ruby on Rails95%
PostgreSQL90%
Node.js / NestJS85%
Redis & background jobs85%
DevOps & Infrastructure85%
PHP / Laravel80%
MySQL / SQL Server80%
Go75%

Experience

Elevation view: most recent position at the top.

workPT Giradia Solusi Digital

Senior Backend Developer

calendar_monthMar 2026 – present
  • ▸Built Bati, a multi-tenant POS SaaS on NestJS and PostgreSQL serving a Flutter cashier app and admin dashboard.
  • ▸Designed offline-first sync using client-generated UUIDv7 keys with idempotent push and cursor-based pull, allowing merchants to sell offline and reconcile without duplicate sales or lost stock.
  • ▸Modeled every cash and stock movement as an immutable event with a derived read model, so corrections are counter-entries rather than edits. Profit and loss, cash flow, balance sheets, shift cash reconciliations, and ledgers are all projected from a single source of truth, preventing retroactive movement.
  • ▸Built a freemium/Pro entitlement layer: features are resolved as package features, cached in Redis, and enforced server-side by feature and quota guards, allowing each report to be sold per flag as an add-on.
  • ▸Shipped an F&B sales pipeline with per-channel and open billing without changing the core checkout flow, enabling multiple POS terminals to serve a single table concurrently without data loss from race conditions.
  • ▸Ran production on Docker/Traefik; made BullMQ scheduled jobs (analytics, subscription lifecycle, notifications) idempotent via deduplication locks.
  • ▸Removed horizontal scaling barriers via a one-time migration service, Redis-backed rate limiting, and S3-compatible storage.
NestJSPostgreSQLRedisBullMQDockerTraefikFlutter
workVirtual Spirit

Senior Backend Developer

calendar_monthMar 2022 – Feb 2026
  • ▸Designed the core domain layer using the Interactor and Organizer patterns, separating business logic from Rails models and controllers, a maintainable foundation that reduced PR review time.
  • ▸Engineered an end-to-end marketplace payment infrastructure on Stripe API and Stripe Connect, implementing destination fees and split payments.
  • ▸Built an automated payment routing pipeline that distributes rent payments from tenants to owners with platform fee capture, eliminating manual reconciliation and delivering same-day payment SLAs.
  • ▸Designed an escrow and subscription billing engine supporting recurring fee payments, hold-and-release flows, and professional services bookings across multiple pricing tiers.
  • ▸Implemented a real-time messaging layer with AnyCable in Ruby on Rails for in-app chat and social media features, tested to maintain 1,000+ concurrent WebSocket connections.
  • ▸Eliminated N+1 query patterns and refactored heavy database loads, adding counter caching combined with Redis caching to lower PostgreSQL latency.
  • ▸Containerized the entire application stack with Docker and Docker Compose, achieving dev/staging/production parity and reducing new-engineer onboarding from 2 days to under 4 hours.
  • ▸Partnered with distributed cross-functional teams (FE, UI/UX, Product) across time zones using Agile/Scrum.
Ruby on RailsPostgreSQLStripe ConnectAnyCableRedisDocker
workPT Weyland Indonesia Perkasa

Engineering Manager

calendar_monthNov 2019 – Feb 2022
  • ▸Promoted from Senior Backend Developer to Engineering Manager after 2 years, with full ownership of technology direction and architectural decisions, and responsible for managing an 8-person engineering team while continuing hands-on backend development.
  • ▸Led the backend for AtozGo, a new on-demand food delivery super-app built as a new product line, achieving over 154,000 monthly transactions with a 92% delivery success rate and IDR 3.76 billion GMV within months of launch.
  • ▸Designed a multi-sided order routing and delivery engine across 9 service domains with real-time push notifications via AnyCable.
  • ▸Led a monolith-to-microservices migration, separating billing and transaction flows into independently deployable services.
Ruby on RailsAnyCableMicroservicesTeam leadership
workPT Weyland Indonesia Perkasa

Senior Backend Developer

calendar_monthNov 2017 – Nov 2019
  • ▸Fully responsible for the backend architecture of a fintech super-app spanning 7 core service domains and 21+ sub-services: bill payments (PPOB), top-up, QRIS, e-money, flight and bus ticketing, transfers, and bank disbursement. Reached a monthly transaction volume over IDR 8.6 billion and 181,000+ transactions/month within two years of launch.
  • ▸Maintained 1,000 TPS with 99.9% uptime during peak utility payment cycles through load balancing on Nginx, horizontal scaling of stateless services, and proactive migration of bottlenecks before incidents.
Ruby on RailsMySQLNginxPayments
workWalden Global Services

Backend Developer

calendar_monthOct 2015 – Dec 2017
  • ▸Core backend developer of ShippingNet, an end-to-end export/import and customs document management platform for a major Indonesian FMCG manufacturer, with 80+ features across export (27), import (23), document handling (7), and master data (23).
  • ▸Built the Import module: PO-based import orders, purchase request (PBI) forms, customs declarations (PIB/PIBK), BPOM and quarantine documents, delivery orders, cargo delivery, freight-rate approval, insurance claims, and SLA/dwelling-time tracking.
  • ▸Implemented role-based access control down to function level (module → submodule → component → function), integrated with the company SSO and the employee/organization master database (MDM).
  • ▸Developed a template-driven email notification engine (20+ event types) and automated PDF/Word generation for shipping and customs documents.
  • ▸Built Excel data import/export and integrations with Oracle stored procedures and an external trade (GLT) API.
  • ▸Improved data management efficiency by implementing database best practices and optimizing complex SQL queries.
  • ▸Served as a technical lead for specific sprints, managing SOW estimations, milestones, and developer assignments.
  • ▸Authored core application skeletons and shared libraries to be utilized by the wider development team to ensure consistency.
Ruby on RailsSQL ServerOracleRBAC / SSO
workPoliteknik Piksi Ganesha

Backend Developer

calendar_monthJan 2014 – Aug 2015
  • ▸Built a comprehensive Certification Management System using Laravel and MySQL.
  • ▸Translated complex business requirements into functional product features while maintaining platform stability.
LaravelMySQL

Featured projects

A selection of recent work and the systems behind it.

Shipping Net: Export and Import Document Management System
2015

Shipping Net: Export and Import Document Management System

Shipping Net is an internal web app for a major Indonesian FMCG manufacturer. It runs the paperwork behind every international shipment. The company exports finished products and imports raw materials, and each shipment needs a dozen or more documents. They come from different teams, government agencies and outside par…

RUBY ON RAILSBACKEND ENGINEERINGPOSTGRESQLSOFTWARE ENGINEERING
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VTRConnect (Virtual Tenant Representation Platform)
2025

VTRConnect (Virtual Tenant Representation Platform)

VTRConnect is a high-performance, international-scale prop-tech platform designed to streamline and automate the property rental ecosystem in the United States. Built using a robust Ruby On Rails, Nextjs, Postgresql, Docker, CI/CD architecture, the platform connects property stakeholders, financial systems, and localiz…

RUBY ON RAILSNEXTJSPOSTGRESQLSTRIPE APISTRIPE CONNECTWEBSOCKET
Details arrow_forwardopen_in_new Live demo
ATOZPAY
2017

ATOZPAY

Atozpay is an enterprise-grade fintech and digital payment gateway platform engineered to drive financial inclusion through micro-transactions and digital billing solutions. The system empowers a dual-layered ecosystem of dedicated transactional Agents and Regular Users, processing millions in Gross Merchandise Value (…

RUBY ON RAILSPROJECT MANAGEMENTBACKEND ENGINEERINGPOSTGRESQLBACKEND SCALE
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How I build

Notes and standards applied across every drawing.

I treat a backend like a set of drawings: explicit contracts, dimensions you can check, and a revision history anyone can read. Domain logic sits in interactors rather than models, money paths are idempotent by construction, and every service ships with the telemetry needed to prove it works.

N1

Contracts before code

Interactor and organizer patterns keep domain logic out of models and controllers, so behaviour is testable in isolation.

N2

Money paths are idempotent

Webhook keys, outbox tables, and event-sourced ledgers, so retries never double-charge or double-pay.

N3

Measured, not assumed

p95 budgets per endpoint, tracing on every hop, and dashboards that a non-engineer can read.

N4

Tests as a foundation

RSpec suites gated in CI on all payment and auth paths, built from the first commit rather than retrofitted.

detail B · request path
  1. edge / load balancer
    nginx · alb
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  2. api service
    rails · go
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  3. domain interactors
    idempotent
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  4. queue & workers
    sidekiq · bullmq
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  5. postgres + redis
    replica · cache

observable at every hop

Have a system that needs drawing up?

Available for senior backend and platform work with remote, cross-functional teams. Reviews, architecture audits, and payment-infrastructure builds included.

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