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amin4udin

Aminudin

@amin4udin

Backend Developer and Pentester, NodeJS, Go, Automation Bots

Indonesia
Indonesian, English
About me
Backend developer with 7+ years building production systems, including 7 years on enterprise microservices at Telkom Indonesia. Certified penetration tester (eWPTX, eCPPT) who found a critical domain takeover in Arweave Name System. I build REST APIs, scrapers, automation bots and SaaS apps with Node.js, Go and TypeScript, and I test web apps and APIs for security holes. Founder of Easy To Learn, a community that teaches bot automation to 1000+ people. Clear written updates, no long meetings needed.... Read more

Skills

a
amin4udin
Aminudin
Offline • 

See my services

API & Integrations
I will build a secure rest API backend with nodejs, nestjs or golang
From$150 / projectMore details
Programming & Tech
I will do web app and API penetration testing with a detailed report
From$60 / projectMore details

Portfolio

Work experience

Perpack_Fulfillment

Full-Stack Engineer

Perpack Fulfillment

Nov 2025 - Present • 11 mos

- Built a returns analytics feature end to end (Go API and Next.js dashboard) for a warehouse system processing about 500K orders per month - Designed a pre-aggregated daily table with a nightly worker, cutting month-range reports from minutes to under a second - Tuned heavy MySQL reports with EXPLAIN ANALYZE, taking key queries from 24.2s to 2.1s - Rebuilt heavy exports into batched, keyset-paginated streaming jobs on a queue - Built order flows with courier integrations, a partner order intake API, and a wallet with payment gateway disbursement Stack: Go, MySQL, Redis, Python (Django), PostgreSQL, Next.js, React, TypeScript

Self-Employed_/ Freelancer

Penetration Tester and Bug Bounty Hunter

Self-Employed / Freelancer

Jul 2022 - Present • 4 yrs 3 mos

Independent penetration testing and bug bounty work on web apps, APIs, Android apps and Web3 platforms. - Arweave Name System: found a critical domain takeover (auth bypass in the token transfer flow). Patched and officially acknowledged - McDonald's Indonesia: reported a misconfigured subdomain exposing database credentials and employee data - Cyclix Games: found a Firestore misconfiguration allowing unauthorized read, write and delete - Audits for NFT marketplaces and Web3 platforms including Endlesss, AirNFTs and Catalog Works - Paid bounties for React2Shell findings. 20+ public writeups on Medium Every report includes a clear PoC, impact and remediation steps.

Telkom_Indonesia

Back-End Engineer

Telkom Indonesia

Jun 2019 - Sep 2026 • 7 yrs 3 mos

- Built microservices for internal enterprise apps: ticketing, product catalog, digital signature processing, and contract document generation and distribution - Maintained and optimized services across multiple repositories for performance and reliability - Integrated third-party services: digital signature platforms, OCR (with the data science team), WhatsApp and email, and other external APIs Stack: Node.js, NestJS, TypeScript, Go, MongoDB, MySQL, PostgreSQL, Redis, Kafka, Elasticsearch, OpenShift