SIMKEU Web.

SIMKEU Web is the company-wide back-office system for a container port terminal in Indonesia. It replaces a legacy Oracle Forms/Reports application with a single web app.

It has more than 1,200 Java classes, more than 700 screens and fragments, and several hundred menus behind role-based access.

• Finance dashboard went from 5.6 s to about 330 ms. I profiled it and fixed four bottlenecks: N+1 queries, missing indexes, repeated view scans, and uncached lookups.
• A budget-allocation list that timed out after 49.8 s now loads normally. The cause was a per-row "already paid" subquery, which I rewrote as one set-based query.
• Static asset delivery: I fixed caching headers on an 8.7 MB application shell that had been re-downloaded on every visit.

Personalia and Payroll, moved from a separate legacy app into the main system.

• Ported the personnel and payroll screens from simpersweb. That covered 73 HR menus mapped to their tables.
• Built and wired 29 payroll reports in PDF and Excel.
• Ran an HR audit that found about 58 issues and wrote 6 fix plans. Risky access rules first ran in a shadow-logging mode, so they could be checked for three working days before being switched on.
• Wrote the HR user documentation: an SOP in PDF and a training deck.

• Finance dashboard: live cash and bank position (closed months plus the open month), 8 financial ratios, and P/L. Every card drills down to the underlying vouchers.
• Human Capital dashboard: headcount and composition, read from one source of truth.
• Fuel (BBM) dashboard: replaced the old fuel issuance log with request tracking and consumption analytics.

I re-implemented about 30 Oracle Reports (.rdf) so the web output matches the legacy printouts figure for figure, including quirks that accountants rely on.

• Balance sheet, income statement and cash-flow reports, with per-account breakdowns
• Receivable, payable and cash-advance aging
• Cash book, sub-ledgers, expense summaries, stock movement and valuation
• A tax report in the 13-column layout the new national tax system (Coretax) requires
• Excel exports with Apache POI and PDFs with iText

• Found and repaired vouchers that were only half posted (header posted, journal lines not). I fixed 301 lines in production after taking a backup, and closed the code path that caused them.
• Reconciled report pairs that should agree but didn't: cash book vs cashier report, inventory GL vs stock movement, stock card vs balance. Then fixed the root causes, including sign conventions, period filters and unposted months.
• Traced wrong inventory values to a ghost stock unit that had inflated the moving-average cost.

• Fixed CSRF token handling across the single-page app and tightened the Content Security Policy.
• Added an account-status check that runs during the session, so disabled users lose access right away.
• Designed a role-based privilege matrix: 26 role classes, 1,314 menu grants, 45 users.
• Fixed multi-stage approval workflows, such as directors who were missing their decision buttons and supervisors who couldn't see documents in their queue.

Integrations

• e-Meterai (digital stamp duty): fixed token handling and serial-number pool management.
• RabbitMQ notification consumer for approval and e-mail events.

Testing and delivery

• Built a Playwright smoke-test harness that clicks through the whole app (all menus and screens) to catch broken pages before release.
• Set up Docker-based local environments and documented the Payara deployment pitfalls.

• Matching a legacy system's results is harder than copying its features. Accountants trust numbers, not screens.
• Most "bugs" in an ERP are business-process gaps: a posting job never run, a missing approval step, master data with no owner.
• Measure before optimizing. One profiling session found the 17× dashboard speedup.