Fajar Maulana Firdaus
Half of my life is full of Indomie and Memories.
The Story Behind The Code
Hey there! I'm not just your typical software engineer – I'm a drummer who traded some of my drumsticks for keyboards (the typing kind, though I still keep the rhythm alive). When I'm not crafting code or architecting systems, you'll find me lost in various digital worlds or creating beats that would make any compiler dance.
Rhythm in My Code
Former drummer of UniFive band, because sometimes you need to debug with a beat!
Digital Adventures
From Dota 2 matches to FIFA championships, and everything in between. Yes, even those heart-stopping horror games!
Storyteller at Heart
Once dreamed of being a novelist. Now I write stories through code, but the plot twists are just as exciting!
Code Craftsman
Turning coffee into code and problems into solutions, one function at a time.
Family First
Proud dad and family man, because the best code reviews come from my daughter's giggles!
Spontaneous Explorer
Unplanned travels are my jam – because the best bugs are found off the beaten path.
Food vs Fitness
In an eternal battle between loving food and trying to stay fit. Food usually wins, and I'm okay with that!
Cat Lover
As a proud cat enthusiast, I believe every day is 'purr-fect' when shared with my feline friends. Their playful antics and soothing purrs inspire me to approach coding with the same curiosity and creativity!
Technical Arsenal
Here are the key technologies and methodologies I work with in my development journey. Each skill represents areas where I contribute to building scalable and maintainable software solutions.
System Architecture & Design
Designing scalable and maintainable system architectures
TypeScript
Type-safe JavaScript development with modern frameworks
React.js
Modern frontend development with hooks and component patterns
Node.js
Server-side JavaScript and API development
Next.js
Full-stack React framework with SSR/SSG
Distributed Systems
Building resilient distributed applications
Microservices Architecture
Designing and implementing microservices patterns
Performance Optimization
System and application performance tuning
Domain-Driven Design (DDD)
Strategic software design and domain modeling
Java
Enterprise application development with Spring ecosystem
PostgreSQL
Database design, optimization, and complex queries
AWS (EC2, EKS, SQS, SNS, Lambda)
Cloud infrastructure and serverless solutions
Kubernetes
Container orchestration and deployment
Docker
Containerization and development environments
Event-Driven Architecture
Asynchronous system design and messaging patterns
Test Driven Development
Test-first development methodology and practices
Technical Leadership
Leading engineering teams and technical decisions
Team Mentoring
Developing junior engineers and knowledge sharing
CQRS
Command Query Responsibility Segregation patterns
Redis
Caching strategies and data structures
Kafka
Event streaming and message processing
Agile Methodologies
Scrum, Kanban, and agile project management
Terraform
Infrastructure as Code and cloud provisioning
Helm
Kubernetes package management and deployments
Datadog
Application monitoring and observability
Go (Programming Language)
Systems programming and microservices development
Python
Scripting, automation, and data processing
C#
Backend development with .NET ecosystem
C
Systems programming and low-level development
C++
High-performance systems and application development
Journey So Far
Software Engineer - Experiments (Super App)
Xendit
February 2023 – Present
- Resolved memory leak in NEX backend, reducing memory usage from 800+ MiB to ~385 MiB (over 50% reduction), cutting memory growth rate from 100%+ to 15%
- Resolved Bank Mayapada (BMI) scaling bottleneck by identifying Node.js crypto blocking operations, implementing caching layer that eliminated CPU saturation
- Designed GCRA (Generic Cell Rate Algorithm) rate limiting for BMI API integration, eliminating rate-limit violations; implemented circuit breaker preventing cascade failures during bank maintenance
- Built NexCash, a white-label E-Money platform designed to enable external brands to offer E-Money products without independent BI licensing — shipped as E-Money-as-a-Service
- Key engineer in securing Bank Indonesia Category 1 license (money account issuance) — drove 2-month regulatory audit engineering workstream with IT GRC, Legal, and Product
- Architected in-house QRIS Acquirer, replacing Dana and LinkAja as third-party providers — Xendit now captures 100% of QRIS MDR revenue (previously retaining only 15–33%)
Software Engineer - Virtual Accounts
Xendit
January 2022 – February 2023
- Integrated 3 new bank channels (DBS Indonesia, DBS Singapore, Bank Neo Commerce) into platform supporting 15+ bank integrations
- Evaluated Philippines market expansion via DragonPay and Standard Chartered Bank to facilitate Xendit's regional growth.
- Integrated DBS Indonesia and DBS Singapore to support Xendit's regional growth.
Technical Lead
Bank BTPN
January 2021 – January 2022
- Led 3 engineering squads (11 engineers) shipping 6 back-office banking applications: Corporate Loans, GL Transactions, Insurance, Payroll (PT Pos Indonesia), Reconciliation, Credit Card Reconciliation
- Built Debit Card reconciliation system ingesting 16 data sources (30K–600K records each), serving Back-End Operations daily
- Proposed and authored Credit Card reconciliation engineering guidelines — established technical foundation before product launch
Developer Digital Product & Service Delivery (Full Stack Developer)
Bank BTPN
October 2019 – January 2021
- Built applications for Back-Office Employees: Corporate Loan and General Ledger Transactions applications.
- Learned Test Driven Development and Pair Programming.
- Contributed to software components using Java and JavaScript.
Computer Lab Assistant
Mobile Innovation Studio
November 2016 – October 2019
- Being a computer lab assistant and administrator on Mobile Innovation Studio.
Software Engineer
Danasyariahid · Freelance
August 2018 - November 2018
- Built and maintained the web application for Danasyariah, a Sharia-compliant investing/crowd funding platform.
- Provided Sharia Investment Services and Financing for business owners and individuals, ensuring Halal benefits while avoiding Maisir, Gharar, and Riba.
Android Developer
Lestari
October 2016 - September 2018
- Developed the Lestari app, a platform designed for the Local Art and Culture Marketplace focused on conserving the local artist and culture in Indonesia.
- Collaborated with cross-functional teams to enhance app features and user experience.
- Utilized Firebase for backend services and implemented Java for Android development.
Web Developer
Telkom Indonesia · Internship
June 2018 - August 2018
- Built SPPD (Surat Perintah Perjalanan Dinas) application using Django, enabling Telkom employees to manage official travel.
Certifications
Improving Database Performance with Amazon ElastiCache for Redis
Educative
2024
Provisioning AWS Resources Using Terraform
Educative
2024
Diabetes Prediction Using Keras
Educative
2024
Getting Started with Amazon Managed Streaming for Apache Kafka
Educative
2024
Mastering Apache Kafka
Educative
2024
Getting Started with Virtual Private Cloud (VPC) in AWS
Educative
2024
Architecting on AWS
Amazon Web Services (AWS)
2022
Essential Domain Driven Design
Virtual Genius LLC
2022