Fajar Maulana Firdaus

My Resume / About Me

A snapshot of my journey, skills, and experiences. I am currently 28 years old.

Professional Summary

Software Engineer with 6+ years in fintech and banking, specializing in payment systems, regulatory compliance, and scalable backend architecture. Built a white-label E-Money platform (E-Money-as-a-Service) and in-house QRIS payment infrastructure (issuing + acquiring) that secured Bank Indonesia Category 1 license. Led engineering teams of up to 11 across 3 squads. Track record of replacing third-party payment providers with in-house solutions to capture full revenue margins.

Key Achievements

Top Performer Award - Product Impact

XenditQ4 2023 - Q1 2024

Recognized as top performer for exceptional contribution to E-Money product development and QRIS payment system implementation, directly enabling major regulated financial services market entry.

Regulatory Compliance Achievement

Xendit2024

Key technical architect securing Bank Indonesia License Category 1 for Account Issuance Service (e-money), unlocking substantial regulated financial services market opportunities.

The YC Award - Customer Success Excellence

Xendit2022

Awarded for exceptional dedication to customer service team support, including debugging complex partner integration issues, providing technical guidance to partners and customers on Xendit integration best practices, and maintaining clear communication with CS team on issue resolution progress.

Technical Skills

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

Work Experience

Xendit

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
TypeScriptDomain-Driven Design (DDD)KrakenDAWS EKSAWS EC2CQRSPostgreSQLKubernetesPgBossHelmTerraformDatadogSentrySplunkNode.js
Xendit

Software Engineer - Experiments (e-money)

Xendit

April 2023 – March 2024

  • 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%)
TypeScriptPostgreSQLReactJsNextJsRedisAlibaba CloudKubernetesHelmTerraformDatadogSentrySplunk
Xendit

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.
TypeScriptGo (Programming Language)PostgreSQLMongoDBRedisRabbitMQKafkaAWS EKSAWS EC2Amazon SQSAmazon SNSKubernetesHelmTerraformDatadogSentrySplunkNode.js
Bank BTPN

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
Spring CloudSpring BootKafkaMicrosoft SQL ServerJavaAngularNode.jsRedis
Bank BTPN

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.
KafkaTest Driven DevelopmentReact.jsMicrosoft SQL ServerJavaPostgreSQLAngularPair ProgrammingReact NativeNode.js
Mobile Innovation Studio

Computer Lab Assistant

Mobile Innovation Studio

November 2016 – October 2019

  • Being a computer lab assistant and administrator on Mobile Innovation Studio.
JavaAndroidFirebaseLaravel
Danasyariahid · Freelance

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.
PHPLaravel
Lestari

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.
FirebaseJavaAndroidLaravel
Telkom Indonesia · Internship

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.
MySQLSemanticUIDjangoPython 3

Notable Projects

Surabaya.py

Surabaya.py is a Python user group in Surabaya, Indonesia. I was a community organizer for Surabaya.py.

PythonCommunity Organizer
View Project →

Lestari

Lestari is a platform designed for the Local Art and Culture Marketplace focused on conserving the local artist and culture in Indonesia.

FirebaseJavaAndroidLaravel

Achievements

  • Winner of FTIF Festival Academy 2017
  • Runner Up in Mobile Apps Development Competition (Vocomfest) 2017

CTF Participation

Participation in various Capture The Flag (CTF) competitions. Capture The Flag is a competitive event where participants are tasked with finding vulnerabilities in a given system and exploiting them to gain access to the flag. Under the ITS CTF team as well as heimdall @ ParadoxicalTheory (https://ctftime.org/team/29984).

Events

  • Gemastik CTF 2017
  • Gemastik CTF 2016
  • Hack The Vote 2016
  • TUM CTF 2016
  • H4ckIT CTF 2016 Online

Certifications

Education

Institut Teknologi Sepuluh Nopember

Bachelor of Computer Science (S.Kom.) in Informatics Engineering

Institut Teknologi Sepuluh Nopember

September 2015 – October 2019

Activities & Achievements

  • Member of ITS music extracurricular
  • Member of ITS Jazz organization
  • Capture The Flag (CTF) competitions
  • Billiards enthusiast
  • Muay Thai practitioner
  • Computer Lab Assistant at Mobile Innovation Studio
  • Teaching Assistant for various courses, including: Network Programming, Operating System, Web Programming, and Mobile Programming.

Languages

English

Professional Working

Indonesian

Native

Community

Surabaya.py

Community Organizer

Surabaya.py

September 2016 – October 2019

  • Organizing events for Surabaya.py to foster growth.
PythonCommunity Organizing