// hello, world

Faisal Lumintang

Senior Backend Engineer · Go · Distributed Systems · AI‑Augmented Engineering

I build high-throughput transaction systems at ByteDance (Tokopedia) — cart, checkout, and order infrastructure serving 100M+ monthly users across Southeast Asia at 99.99% uptime. These days I also wire LLMs into production: MCP integrations, AI-driven debugging, and incident response that assembles on-call engineers before a human even notices.

View projects Download résumé
7+years of Go in production
100M+monthly active users served
1M+orders processed daily
99.99%uptime on core services

// side projects

Things I build after hours — each one live on its own corner of this domain.

❤️‍🩹 health.faisalmerfin.dev ↗

Health Dashboard

A personal health pipeline: an AI agent on Telegram logs meals, workouts, and weight into Notion, then renders it all as a live dashboard — calories vs. 7-day average, steps, training volume, and weight trends.

AI AgentTelegramNotionData Viz
🃏 optcg.faisalmerfin.dev ↗

OPTCG Tracker

One Piece TCG collection manager with AI-powered card scanning — point a camera at a card, let the model identify it, and track the collection. Backed by Supabase, with a Telegram bot companion.

AI VisionSupabaseTelegram Bot
🎭 web-based-vn.faisalmerfin.dev ↗

After School — Visual Novel

A visual novel that runs entirely in the browser — story, branching dialogue, and scenes with nothing to install. Press play, make choices, see where it goes.

Web GameVisual NovelInteractive Fiction

// experience

Feb 2024 — Present

Senior Software Engineer · ByteDance (Tokopedia)

  • Own Tokopedia's Shopping Flow services post-acquisition — marketplace cart, checkout, wishlist, and unified order history — serving 100M+ MAU.
  • Wired MCP integrations connecting LLMs to checkout and order APIs: the system detects anomalies, diagnoses downstream failures, and auto-assembles on-call engineers in a Lark channel without human intervention.
  • Completed a zero-downtime AWS → ByteCloud migration of all Shopping Flow services and 10+ TB of order data.
  • AI-assisted development (TTADK, Trae) now covers ~80% of implementation — my focus shifted to system design and code review.
Jul 2023 — Feb 2024

Lead Software Engineer, GTP · Tokopedia

  • Led 6 engineers on the General Transaction Platform — shared cart-checkout-order infrastructure for 20+ non-marketplace verticals on 5 Go microservices.
  • Config-driven design cut new-business onboarding from months to weeks; most new verticals shipped with zero custom code.
  • Kept order history at 300 RPS and 1M+ new orders/day at 99.99% uptime via multi-layer redundancy.
Jul 2021 — Jul 2023

Senior Software Engineer · Tokopedia

  • Core contributor designing the Unified Order History from scratch — consolidating 30+ business verticals at 1M+ orders/day.
  • Halved marketplace cart latency (>6s → ~3s) through query optimisation and caching.
  • Mentored and onboarded 6 engineers; drove code-quality culture through structured reviews and ATDD.
May 2019 — Jul 2021

Software Engineer · Tokopedia

  • Built the Transactionapp FSM engine and shipped Unified Order History v1, unifying all Tokopedia order types.
  • Integrated Shariah-compliant (Umrah) flows; built an ATDD framework adopted team-wide.
  • Took part in the Alibaba Cloud → AWS migration of all Shopping Flow services during the GOTO IPO.
May 2016 — Apr 2019

Full Stack Engineer · PT. Digerati Atomic Indonesia

  • Delivered 7 client projects — POS, B2B, and manufacturing apps — across PHP Laravel, React, Angular, and C#/.NET.

// inventions & publications

Four invention publications filed at Tokopedia / ByteDance.

  • Achieving High Availability Using Multiple Data Stores in Transaction List
  • Handling Multiple Update Requests to Frequently Updated Data Using Duplicate & Stale Checker
  • Unified Order List System
  • Centralized Multiple Products & Services Order State Management and Notification Systems

// toolbox

Language

Go — 7+ years

Data

PostgreSQLMySQLCockroachDBYugabyteDBRedisElasticsearch

Messaging & APIs

KafkaNSQgRPC / ProtobufREST

Platform & Infra

DockerKubernetesAWSByteCloudCI/CDGitOps

AI & Automation

LLM / MCP integrationTTADKTraeAutomated incident response

// education & certifications

B.Sc. Computer Science

BINUS University · 2012 — 2016 · GPA 3.6

Certifications

Developing on AWS (2020) · Architecting on AWS (2020) · Forward Business Agility

Languages

English — fluent · Indonesian — native

// contact

Let's build something that doesn't fall over at scale.

Based in Jakarta, Indonesia — open to relocation (visa sponsorship required).

faisalmerfin@gmail.com LinkedIn GitHub