Omnichannel messaging
WhatsApp, SMS and Email from one platform. Broadcast, scheduling, delivery tracking, inbox, ticketing and auto-reply, plus cross-channel fallback when a channel fails.
Indrico Jowensen Backend Software Engineer
I build backends that deliver — every message, every time.
6+ years building and running production systems for enterprise clients in banking, insurance, logistics and government. I specialize in omnichannel messaging, high-volume APIs, and the queues, webhooks and databases that keep them running.
- years building & operating production systems
- 6+
- transactions a day on one messaging platform
- 100K+
- of MySQL records tuned for high-volume workloads
- Millions
- channels: WhatsApp, SMS & Email
- 3
- industries served, all enterprise clients
- 4
Built for enterprise clients in
- Banking
- Insurance
- Logistics
- Government
01 About
Most of my work happens where users never look.
The queue that absorbs a sudden spike. The webhook that quietly syncs a delivery status. The index that makes a heavy query fast again. That's where I do my best work.
For more than six years I've built and operated production systems for enterprise clients across banking, insurance, logistics and government. That includes a multi-tenant omnichannel platform that moves 100K+ transactions a day across WhatsApp, SMS and Email.
I like owning things end to end. I design the flow, write the code, ship it, and stay with it in production. That means tracking down database contention, draining worker backlogs, and fixing webhooks when they fail at the worst possible moment.
Employer and client names are withheld to respect confidentiality agreements.
02 Expertise
Areas I know inside out
Six areas I've owned in production, day in and day out.
APIs & webhooks
High-volume REST APIs and provider integrations: the WhatsApp Business Platform and third-party messaging gateways, with inbound webhooks that keep every delivery status in sync.
Async processing & queues
Queue-based processing with workload-specific workers and a durable outbox, so no job silently disappears. Backlog monitoring raises an alert before users notice anything.
Database performance
MySQL with millions of records. I do query and index optimization for high-volume workloads, and I hunt down contention and heavy queries in production.
Security & encryption
Database- and application-level encryption for sensitive enterprise data, built for clients in regulated industries like banking and insurance.
Infrastructure & Linux
Ubuntu, Nginx and KVM administration: networking, process supervision and monitoring, and moving legacy servers onto virtual machines without rewriting the app.
03 Selected work
Case studies, anonymized
Real production work, without the names. The only figures here are ones from systems I actually worked on.
01
Messaging platform · Multi-tenant
An omnichannel messaging platform for enterprise tenants
- Challenge
- Many tenants, three channels, and 100K+ transactions a day. Every message has to be sent, tracked, and rerouted if its channel fails.
- What I did
- Built and maintained the messaging workflows end to end: broadcast and scheduling, queues, delivery tracking, provider webhooks, a shared inbox, ticketing, auto-reply and cross-channel fallback. I also integrated the WhatsApp Business Platform and third-party messaging providers, including delivery-status sync.
- Outcome
- One multi-tenant platform serving enterprise clients across four industries and handling 100K+ transactions per day.
02
Architecture · Reliability
Queue architecture with a durable outbox
- Challenge
- Workloads have different urgency. A large broadcast shouldn't hold up a time-sensitive message, and no job may silently disappear.
- What I did
- Designed queue-based async processing with workload-specific workers, durable outbox processing, backlog monitoring and operational alerts through Sentry and Telegram.
- Outcome
- Isolated workloads, and backlogs or failures that arrive as alerts instead of surprises.
03
Data · Performance
Keeping a multi-million-row MySQL fast
- Challenge
- High-volume workloads on tables with millions of records led to heavy queries, database contention and worker backlogs.
- What I did
- Optimized queries and indexes for the hot paths, and investigated contention and application performance directly in production.
- Outcome
- Resolved production issues involving contention, heavy queries and worker backlogs, fixed at the root rather than patched over.
04
Infrastructure · Migration
Rescuing a legacy Ubuntu production server
- Challenge
- A production system on a legacy Ubuntu release. The original developer had left, and there was little room to change the application.
- What I did
- Migrated the system into a KVM virtual machine and configured networking, IP assignment and automatic VM startup.
- Outcome
- The legacy application kept running with minimal application changes, on infrastructure that can be managed and restarted predictably.
05
Frontend · Modernization
Modernizing a legacy React frontend
- Challenge
- A React app still built on Create React App, which is no longer maintained, with a dependency tree that no longer resolved cleanly.
- What I did
- Migrated it to React 19 with Vite, replaced incompatible libraries, and used automated parity testing to preserve the existing UI and behavior.
- Outcome
- Validated 200+ automated tests and production builds while preserving the existing UI and behavior.
04 Experience
Experience & education
-
2020 — Present
Software Engineer
Enterprise software company name withheld · NDA
- Develop and operate production systems for enterprise clients in banking, insurance, logistics and government.
- Build and maintain a multi-tenant omnichannel platform (WhatsApp, SMS, Email) handling 100K+ transactions per day.
- Own messaging workflows end to end: broadcast, scheduling, queues, delivery tracking, webhooks, inbox, ticketing, auto-reply and cross-channel fallback.
- Design queue-based async processing with workload-specific workers, a durable outbox, backlog monitoring and alerts.
- Manage and optimize MySQL databases with millions of records. Implement database- and application-level encryption.
- Migrated a legacy Ubuntu production system to KVM virtualization with minimal application changes.
- Modernized a legacy CRA-based React app to React 19 with Vite, replacing incompatible libraries and using automated parity testing to preserve existing UI and behavior; validated 200+ automated tests and production builds.
- Modernized a legacy Laravel application from PHP 7.4 and Laravel 8 to PHP 8.5 and Laravel 13, updating dependencies, adapting application code, configuring PHP-FPM/CLI runtimes, and validating workers, schedulers, and critical workflows with backup and rollback procedures.
- Banking
- Insurance
- Logistics
- Government
-
2020
Bachelor of Information Technology
Universitas Buddhi Dharma
- Graduated with a 3.89 GPA.
- Served as a lecturer assistant for Business Intelligence courses.
05 Stack
Tools I reach for daily
Proven, well-understood technology, used deliberately.
Backend
- PHP
- Laravel
- Node.js
- REST APIs
- Webhooks
- API integration
- Async processing
Messaging
- SMS
- Delivery tracking
- Fallback
Database
- MySQL
- SQL optimization
- Large-scale data
- Encryption
Architecture
- Multi-tenant systems
- Queues
- Provider integration
- Durable outbox
Infrastructure
- Ubuntu
- Docker
- Nginx
- KVM
- Networking
- Linux administration
Frontend
- JavaScript
- React
- React Query
- Vite
- Tailwind CSS
Tooling & ops
- Git
- Postman
- Supervisor
- PM2
- Codex
- Claude
- Telegram monitoring
“Reliable systems are built from tools you understand deeply, not from whatever is newest.”
06 How I work
Four habits I bring to every system
01
Own it end to end
From the first commit to production troubleshooting, I build it, run it, and fix it when it breaks.
02
Design for failure
Providers go down and webhooks arrive late. Queues, outboxes and fallbacks turn that into a non-event.
03
Observable by default
If a backlog grows or a worker dies, I want to know first. Monitoring and alerts ship with the feature, not after the incident.
04
Protect the data
Clients trust us with their data. Encryption and careful access control are defaults, not add-ons.
07 Contact
Let's build something reliable.
Want to talk backend systems? Tell me about your team and what you're building. Messages from this form go straight to my inbox.
- Based inGreater Jakarta, Indonesia
- TimezoneGMT+7 (WIB)
- FocusBackend · Messaging · Data
- Core stackPHP · Laravel · Node.js · MySQL