#PostgreSQL

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 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.

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.

The Laravel core of a document-signing platform: it owns users, identities, organisations, client systems, documents and their signed versions, stamps, and certificates, and orchestrates the services that sign, timestamp, render, and store — without ever holding a file.

A Rust timestamp authority that stamps a document's hash with a signed, NTP-backed time per RFC 3161, so PDF signatures stay verifiable after their certificates expire — issuing and renewing its own signing certificate, with public OCSP and CRL.

An issuing certificate authority in Rust that gives each PDF signer a certificate of their own, then answers every reader's question — is it still valid? — through a public OCSP responder and revocation list, and hands the signing service each key and chain as PKCS#12.

A Rust service that serves Indonesia's administrative regions — 38 provinces down to 83,768 villages, keyed by the official Ministry of Home Affairs codes — as four cascading lookups with search, so every address form in every project gets the same answer.

Four commands that move a stack from its old layout into a new structure across major versions: export without changing the source's data, import each store the way its version allows, verify what really arrived, and rename modules while moving their data along.

One command that rotates an environment's internal credentials key by key: a dry run by default, a backup first, a unique value for every key, a real login to prove each credential that can log in, and rollback for any that fail.

Three commands that back up a running Docker stack — PostgreSQL, MinIO, and Elasticsearch — without downtime, restore it to any point, and keep retention safe, with exit codes that say how much a failure matters.

The procedure that gives a new project its whole infrastructure from generators, in the order the stacks depend on each other: log first, then storage and broker, then the gateway, then the application — with the public steps kept manual.

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.

Every new project needs a gateway, sign-in, and a first administrator before its backend exists. One generator command now builds that stack, working on first boot, by handling the values that fail silently when set by hand and a rerun that would keep the old database.

Its software reached the end of support, and its records must outlive it. One component rewrote data as it read it, so the migration copies rather than converts — an operation with no rollback has to be survivable, not merely careful.

Staging and production shared 136 keys, but 21 had to stay different, including the one that decrypts years of data. Promoting a release's structure, not a file's contents, keeps that key in place and stops a schema migration from silently never running.

One rotation reaches seven services, and a value elsewhere can look exactly like one of their credentials, so search-and-replace could break an integration nobody watches. Working from an explicit list keeps the rotation inside its blast radius and away from the keys that only decrypt.

A Business Continuity Plan stated as two numbers — an RPO of six hours and an RTO of seconds for the data — and the few small scripts behind them: full and incremental backups, one technique per data store, restore as the only test that counts, and config treated as data.