01
Backend systems
APIs, queues, caching, and the decisions that connect services.
TypeScript · Java · GoHELLO, I’M
Fajar Maulana
Firdaus.
Software engineer. Writer. Dad.
I build backend systems, work across the stack, and write about what I learn. This is my corner of the internet for the work, the notes, and the life in between.
Senior Engineer at DKatalis
Now
Always a work
in progress.
Surabaya, Indonesia
01 / THE WORK
From backend systems
to the browser.
Building software across payments,
products, and the systems underneath.
02
Payment infrastructure
Wallets, virtual accounts, and integrations that move money.
PostgreSQL · Redis · Kafka03
Across the stack
From service logic to the interface people use every day.
React · Next.js · Node.js02 / THE JOURNAL
Thinking out loud.
Writing it down.
Software, career, and the parts of life that shape the person behind the keyboard.
Explore all the writingCryptography
[Crypto: age] How Long Does a Passphrase Attack Take?
Calculate age passphrase attack times, understand the assumptions, and see why random selection matters more than password length alone.
7 min read
Personal
Four Years at Xendit, and a Mutual Termination Agreement
I'm leaving Xendit via a Mutual Termination Agreement. The honest version of what happened, what I built, and what comes next.
17 min read
Algorithms
Leetcode - Merge k Sorted Lists Solution
Compare sequential, pairwise, and heap methods for merging sorted linked lists.
5 min read
03 / OFF THE CLOCK
A little life,
between the lines.
The laptop closes. There's a family, a football team to manage, and usually something playing in the background.
More than thejob description.
Dad life
Kiara keeps me busy and inspired. She has her own little corner of the internet, too.
Meet KiaraOne more match
Football Manager, FIFA, and a quieter life on the farm in Story of Seasons.
Find me on SteamKEEP IN TOUCH
Good conversations
start with hello.
Not actively looking, but always happy to connect.
Made with care. Always in progress.Back to the top