Hi, I’mAgung Budi Santoso

Warehouse inventory built around an auditable stock ledger, with a nightly job that fits a per-product OLS regression and backtests it using WAPE, MAE, MAPE and RMSE.

• Laravel 12
• Inertia.js
• Vue 3
• OLS Linear Regression
• PHPUnit

• 505-test PHPUnit suite on in-memory SQLite, covering ledger invariants, authorization boundaries and the regression maths.
• Every stock mutation funnels through one transactional service that locks the product row, making the stock balance invariant structural rather than a convention.
• Nightly ETL chains aggregation and per-product regression with Bus::chain(), then scores past forecasts on WAPE, MAE, MAPE, RMSE and bias.
• Two frontend-guard tests parse every .vue file, catching unbound identifiers that Vite transpiles silently and that would otherwise fail only in the browser.

Event ticketing with guest checkout, Midtrans payments and QR-coded e-ticket PDFs. Led a five-person team across product, development and QA, authoring 97 of 125 commits.

• Laravel 12
• Midtrans Snap API
• QR Code E-Ticket
• Docker
• GCP Cloud Run

• Led a five-person team as product owner, full-stack developer and QA, authoring 97 of the 125 commits.
• Guest checkout alongside registered accounts — a buyer never has to create an account to complete a purchase.
• Payment lifecycle handles the awkward parts: time-limited orders, a scheduled orders:clean-expired pass that expires overdue pending payments inside a transaction, and webhook-driven status updates.
• Multi-stage container image (php:8.2-fpm build to php:8.2-fpm-alpine runtime) with nginx and supervisor running app, queue worker and log viewer as separate processes.

Next.js tool that detects APA, Harvard, IEEE and MLA citations, normalises them, and matches them against Crossref, OpenAlex and Semantic Scholar. Results stream back as newline-delimited JSON, so each reference appears the moment it is verified rather than after the whole batch.

• Next.js
• React
• TypeScript
• Crossref API
• OpenAlex API
• Semantic Scholar API
• Vitest
• Vercel
• NDJSON Streaming

• Streaming NDJSON verification endpoint (application/x-ndjson) that emits each result as it completes, so a batch of twenty references never blocks on the slowest one.
• Chained provider fallback across Crossref, OpenAlex and Semantic Scholar, with 429 retry on Crossref, behind a single academic-provider interface.
• Zero runtime dependencies beyond React and Next.js — the citation parser, style detector, matcher and CSV writer are all first-party.
• Confidence scoring grounded in field-level evidence, including journal abbreviation handling (J. versus Journal) and explicit detection of contradictions between sources.