Hi 👋, Najmi's Here
A backend developer.
I love the way machines work — how a message leaves one system, crosses three more, and still balances at the end. Most of my work is Java and Spring Boot: middleware, e-wallets and payment rails.
I made this website to share my code journey and the things I have built — client work under Professional, my own projects under Personal. A blog about the job is probably coming too.
– Friedrich Nietzsche
Tooling System
- Languages
- JavaTypeScriptJavaScriptPython
- Frameworks
- Spring BootNode.jsExpress.jsReactNext.js
- Data
- OraclePostgreSQLMongoDBRedis
- Integration & Ops
- Apache KafkawebMethodsDockerRHEL
- AI
- ClaudeHermes
Experiences & Projects
Internal E-Wallet Product
Technical Consultant & Team Lead · Indivara · Dec 2025 — Present
Led the convergence of two separate wallet codebases serving the Philippines and Indonesia into a single runtime-configurable platform, driven by a YAML country configuration that decides which market-specific behaviours apply per deployment.
- Designed the core balance model with three configurable modes — standard, shared and closed loop — serving as the single key behind every transaction and reporting flow.
- Built country-pluggable integration layers so one codebase can switch QR standards (QRIS and QRPH), route to different payment gateways and apply market-specific KYC by configuration.
- Led a 6-person team through SIT and UAT across two country environments while contributing directly to backend development, delivering phase 1 to production go-live.
- Cut phase 2 development time by ~35% against the original estimate by integrating AI-assisted coding into the team's delivery workflow.
Middleware Integration System
Team Lead · Indivara · Apr 2025 — Present
Promoted from developer to Tech Lead mid-project to take over a platform migration at an export-import financial institution — replacing MuleSoft with IBM webMethods and moving the legacy Middleware Payment System onto a React and Spring Boot stack.
- Led a cross-functional team of up to 8 through development, SIT, UAT and production go-live, owning technical and business issue resolution through to launch.
- Drove a design change that removed a redundant webMethods installation on the government partner's infrastructure — cutting licence costs, removing a network hop from the transaction path and consolidating logs inside the bank's environment.
- Designed a message bridge resolving format conflicts between SWIFT and RTGS flows so both rails reuse a single shared service instead of duplicate implementations.
- Owned end-to-end deployment across SIT, UAT and Production — NGINX for the React frontend, systemd units for the Spring Boot services, plus Kafka and Redis.
API Gateway Project
Technical Consultant · Indivara · Jan 2025 — Apr 2025
Independently built an ISO 8583 ↔ SNAP message converter against the bank's core system specification, delivering eight services spanning inquiry, intrabank and interbank transfer, settlement, echo and status check.
- Built the asynchronous callback pipeline forwarding core-system results to client callback URIs, with a scheduler-driven status check that reconciles transactions when no callback arrives within a minute.
- Implemented ISO 8583 over a multiplexed TCP/IP connection, correlating concurrent request–response pairs by composite key on one persistent socket instead of a connection per transaction.
- Migrated database version control from Flyway to Liquibase across multiple services and 20+ changelogs, converting scripts to a database-agnostic format.
- Set up Dev, SIT and UAT on RHEL end-to-end — Oracle Database, Kafka in KRaft mode, Redis and NGINX.
Internal E-Wallet Product
Technical Consultant · Indivara · Dec 2024 — Mar 2025
Built transaction and onboarding services for the internal e-wallet, from the member Register API through to Kafka-based transaction workers.
- Developed a general-purpose Balance Deduction System supporting direct-deduct transaction mechanisms.
- Built an inbound–outbound rule management system for principal and CO accounts over Kafka messaging.
- Developed a QRIS Translation API in compliance with Rintis QRIS specifications.
- Designed and optimised reporting with SQL and JasperReports, supporting Excel, CSV and PDF exports.
SME Suites
Technical Consultant · Indivara · Nov 2024
Developed integration APIs connecting a range of SME platforms, including merchant applications and payroll or payment systems.
- Implemented the initial Kafka-based Request–Reply communication pattern across multiple internal systems.
- Refactored existing code to improve reliability, maintainability and performance.
Internal Middleware Payment Rail
Technical Consultant · Indivara · Mar 2024 — Dec 2024
Developed BI-SNAP compliant middleware services — internal and external inquiry, interbank transfer transaction history and QRIS CPM.
- Enhanced Spring Boot OAuth2 authentication to meet BI-SNAP authentication standards, and integrated with the Mandiri API.
- Built an ISO 8583 message converter for interoperability with SNAP specifications and back again.
- Ran stress testing with Locust, scripting transaction scenarios, alongside Kubernetes scaling operations to evaluate resilience.
- Co-designed and developed the AVM dashboard, focusing on task list management.
E-Wallet for Bank of the Philippines
Technical Consultant · Indivara · Jul 2023 — Dec 2024
Built transaction features for a Philippine bank's e-wallet, centred on a Kafka-driven Balance Deduction System.
- Implemented balance deduction backing the Send Money and Request Money between member features.
- Developed and integrated the peer-to-peer outgoing transaction inquiry process.
- Built the Account Upgrade feature, connecting bank online accounts to the e-wallet ecosystem.
- Engineered and integrated a cardless withdrawal transaction feature.