Muhammad Restu Utomo

Backend engineer, writing down how systems actually work.

Currently a Backend Engineer at Paques, based in Jakarta, Indonesia. This site doubles as a portfolio and a personal engineering library — one deep-dive topic at a time.

I studied International Business at Universitas Surabaya (UBAYA), then switched into software through Hacktiv8's Full Stack Web Development bootcamp in 2018. Since then I've worked almost entirely on backend systems — Node/Express early on, then Java Spring Boot and Spring WebFlux microservices at scale, and more recently Golang, plus the databases, queues, and observability stack around them.

I like understanding things down to the mechanism, not just the API surface — which is also why the Learning notes section of this site exists.

Experience

Jul 2026 — Present

Backend Engineer · Paques

Apr 2023 — Jul 2026

Senior Backend Engineer · Catalyst

Built and maintained back-end services for Jamtangan.com using Golang, GraphQL, REST APIs, Redis, RabbitMQ, MySQL, and PostgreSQL; transformed legacy code to cut latency from 5+ seconds to under 1 second while pushing throughput past 200 requests/sec, and documented API contracts, led internal training sessions, and worked with leadership on code standards.

Nov 2021 — Mar 2023

Backend Engineer · Ajaib

Built and maintained microservices in Spring MVC and Spring WebFlux against MySQL, integrated third-party banking services, used Kafka for inter-service communication, and monitored production through New Relic, Grafana, and Loki.

Nov 2019 — Nov 2021

Senior Backend Engineer · Nimbly Technologies

Worked across web and mobile early on — React and React Native — then moved into backend: serverless REST APIs on Firebase Cloud Functions with Node.js/TypeScript, a Firebase-to-MongoDB migration, a next-generation REST API on Google Cloud Functions and Google App Engine (including a Golang service), and automated data-compilation jobs via Cloud Scheduler and Cloud Tasks — improving API fetch times by 20% and cutting an "issue flag" calculation from minutes down to about 11 seconds.

Sep 2018 — Nov 2019

Back End Developer · Nimbly Technologies / Sustainnovation Group