Solution Architect · Backend Engineer · Embedded Systems
I design systems as a solution architect and lead the teams that build them, while still writing the core myself — from RISC-V firmware and PCB design to Rust backends, PKI and certificate authorities, and the Linux infrastructure that runs them.
Areas I write about most, by number of articles.
Small tools and scripts I wrote to solve my own recurring problems.
How I write and structure code that stays cheap to change: naming, functions, errors, tests, and architecture — across languages.
Keeping data recoverable: backup strategy, restore procedures, retention, and business continuity.
Counted from the articles and papers that use each technology.
Projects, modules, tools, and architectures I have built.
PoE32 Lite v3 is a small RISC-V board that takes its data and its power from one Ethernet cable, now with the whole PoE power path on the board. It failed out of the box: why, how it runs with jumper wires, and where v4 goes.
The personnel information system of the City Government of South Tangerang: employees keep their own records and follow their services, administrators work on exactly their part of the organisation, and every rule comes from the regulation that sets it. Led and built by me since 2023.
The Vue browser application of a civil-service personnel system: a self-service portal where employees keep their records and propose changes, and administration of a versioned organisation chart, reference data and accounts — built from a few shared definitions, not a page per record.
The Laravel core of a civil-service personnel system: employee records and career histories, self-service proposals with review, salary-step, promotion and retirement decisions, rules taken from regulations, a versioned organisation chart, and access scoped down to a single unit.
The front end cap of the PoE32 enclosure: a bare PCB with no traces and no components, whose only job is to close the aluminium profile and put the RJ45 exactly where it belongs, cut precisely by the board house.
The rear cover of the PoE32 enclosure that also turns PoE32 into a fire alarm node: it powers and resets a detector line from 24 V and reads normal, alarm, and a broken line from a single analog input.
Administrators of a city government's personnel system must each touch only their part of it: everything, one agency, or one unit. I made the scope data — a grant is user, role and scope — checked by one rule, requested and approved by different people, and expiring on its own.
An organisation chart that changes by regulation is still master data for relational records. I keep it in SQL as a table that points at itself, with versions per agency and effective dates, read it with one query and recursive CTEs, and leave drawing it to the interface.
Money crosses every layer of my systems: database, services, JSON, browser and printed documents. I keep one convention everywhere — amounts are integers in the currency's minor unit, as ISO 8583 carries them, named with a suffix, rounded in one place and converted only at the edges.
Salary tables, salary steps, promotion, retirement age and allowances are set by regulations that keep changing. I read the regulations themselves, store what they change as data with an effective date, and keep the arithmetic in code that cites its legal basis.
A personnel database that never enforced its rules had to become clean data for a new system while the old one kept running. Ordered, repeatable phases behind a read-only door, explicit maps, honest placeholders and a report instead of a crash made that possible.
Templates come from real stacks, and copies quietly carry their data, keys, open databases and root-owned paths. My database, object storage and application generators leave the old data, keys and access behind, and read each application's facts from the application itself.
In my day job I work as a solution architect. I design the system, lead the team that builds it — quality assurance, backend developers, a UI developer, DevOps and DevSecOps — and write the most critical modules myself, such as a certificate authority, a long-term PDF signer, and the core API of a personnel system.
I work across the whole stack that a running system actually needs. On the hardware side that means PCB design, microcontrollers, and embedded firmware — including RISC-V boards running FreeRTOS and Embassy, speaking MQTT over mutually authenticated TLS on a microcontroller with 64 KB of SRAM.
Most of my day-to-day work is software: Rust backends and API modules built on Clean Architecture, an OAuth2/OpenID Connect authorization server written from scratch, PAdES document signing, and certificate authorities — root CAs, timestamping authorities, and OCSP responders. I also build the frontends that sit on top of them.
Running all of that means infrastructure: Docker Compose stacks, networking, Mikrotik and RADIUS, observability with OpenTelemetry, and a steady habit of writing command-line tools and utilities for Linux when the existing ones do not fit.