Incident
Payment idempotency: lessons from a Rp40 million incident
3 Oct · 12 min read
Memuat halaman
For engineers & tech creators
1:1 mentoring, technical writing, and e-books drawn from years of building systems. Engineers who want to level up pay for the way you think.
Free to start. Buyers pay the service fee, so your price reaches you in full.
Catatan Arief
Senior engineer · Makassar
You could be:
Junior engineers often ask for your time to talk about careers and architecture.
Your technical posts on LinkedIn get attention, but it stops at likes.
You've explained the same things many times: how to review a PR, how to make senior.
Your system design notes could fill a book, but they're still scattered across Notion.
Example page · Illustration
Arief is a fictional persona, a senior engineer in Makassar. He still shares for free on LinkedIn, while engineers who want deeper guidance buy his e-book or book mentoring here.
Catatan Arief
Senior engineer · Makassar
Building systems that last, not just systems that run.
I'm Arief. Ten years building payment and logistics systems. Here I write, mentor engineers, and sum up the expensive lessons.
Incident
Payment idempotency: lessons from a Rp40 million incident
3 Oct · 12 min read
Design
How to write a design doc people actually read
25 Sep · 8 min read
Career
From senior to staff engineer: what actually changes
17 Sep · 10 min read
E-book
System Design for Indonesian Engineers
E-book · PDF · 9 chapters
System Design for Indonesian Engineers
Case studies from payment systems, order queues, and notifications, written from mistakes that really happened in production. The PDF is sent automatically once payment is confirmed.
Engineering Career Mentoring
1:1 session · 60 minutes · online
System Design Mock Interview
1:1 session · 60 minutes · online
Technical Design Review
1:1 session · 90 minutes · send your design doc before the session
Career Mentoring · 60 minutes
Rp250,000 · paid when booking · WITA
Workshop: Writing a Design Doc
Saturday, 10.00 WITA · online · 40 seats
Engineering Career AMA
Saturday, 19.30 WITA · online · register first
Talk: payment idempotency at scale
YouTube · embedded on the page
Friday Engineering Letter
auto_awesomeNewsletterOne technical essay and one career question I answer every Friday. Free.
Like how Catatan Arief is laid out?
The Editorial layout is preselected when you sign up. You still choose your own content, colours, and blocks, and you can switch layouts any time.
Work you can create
AI can write a function. What it can't replace yet is your judgement: when a design will fall over, and how an engineer's career grows.
1:1 mentoring
60 minutes for the one career question you're facing now
Junior and mid-level engineers pick a slot on your calendar, pay upfront, then meet you online.
Design review
Design doc sent ahead, then taken apart together for 90 minutes
Small teams, or engineers leading their first project, get a second opinion before they build.
E-book · PDF
System Design for Indonesian Engineers
The Notion notes you've collected for years, tidied into chapters. Delivered automatically and protected.
Blog
Payment idempotency: lessons from a Rp40 million incident
Long-form writing that lives on your own page instead of sinking in a feed. Readers arrive, then subscribe.
Online workshop
Writing a Design Doc · Saturday morning · 40 seats
A paid workshop with a seat limit, or a free AMA to introduce yourself to new engineers.
Online class
System Design from Zero · 6 video modules
The material you keep repeating in mentoring, recorded once and available to learn any time.
Example journey · Illustration
Here's Arief's journey over six months. It's fictional, but you can take every step with the features available today.
First week
“I moved my best LinkedIn posts to my own blog, with a newsletter sign-up form.”
320 newsletter subscribers
First month
“Juniors who used to ask over DM now pick a mentoring slot and pay upfront.”
14 sessions paid upfront
Third month
“My system design notes in Notion finally became an e-book. I share the first chapter for free.”
210 e-books sold
Sixth month
“The design doc workshop runs once a month. Mentoring, the e-book, and workshops feed each other.”
Rp11,400,000 this month
Buyers pay the service fee at checkout, so it never comes out of your earnings. Upgrade to lower the service fee your buyers pay.
See all plansPemula
Free
5% service fee, paid by the buyer
Pro
Rp 99.000 / month
3% service fee, paid by the buyer
Studio
Rp 299.000 / month
1% service fee, paid by the buyer
No. The Pemula plan is free. Buyers pay a 5% service fee at checkout, so the price of your mentoring and e-book reaches your wallet in full. On Pro the service fee is 3%, and on Studio it's 1%.
You choose the days and times you're available, for example only Tuesday evenings and Saturday mornings. Engineers pick from those slots and pay when they book, and a booked slot can't be booked twice.
The file is stored privately, and buyers get a short-lived download link once payment is confirmed. If you find your e-book being redistributed, report the case with evidence from your dashboard.
Sales land in your Berdikari wallet once payment is confirmed. From there you request a withdrawal to your bank account, and our team processes it after review. Withdrawals cost Rp5,000 on the Pemula plan and are free on Pro and Studio.
All kinds of creators and brands use Berdikari. See the one closest to you.
See all solutionsMove over one of your best posts, open mentoring slots, and turn your notes into an e-book. Share one address on your LinkedIn and GitHub profiles.