Project Portfolio

Architecture & Data

• Comprehensive REST API covering auth, people, families, events, groups, check-ins, giving, services, forms, reports, and 3rd-party integrations
• Granular RBAC: 12 roles, 48 permissions across 10 modules with [RequireModule] attribute-based backend gating
• JSONB archival system — 71% data reduction (61,927 checkins into 105 JSONB rows) with event-date-based retention and VACUUM FULL post-archival via weekly cron
• Two-tier audit framework — Tier 1: automatic field-level change tracking via EF Core SaveChangesInterceptor on 11 entities. Tier 2: explicit admin action logging with IP address capture
• 12-feature modular flag system (7 included + 5 add-on) with [RequireModule] backend gating, ModuleRoute frontend gating, and 5-minute TTL cache

Payments & Communications

• Stripe (one-time + recurring subscriptions via Payment Intents API) & PayPal (Orders v2) with cover-fees calculation (2.9%+$0.30 card, 0.8% ACH capped at $5)
• Twilio SMS — phone verification, toll-free messaging, SMS-to-Give webhook with keyword triggers ("CONNECT"/"HI"/"HELLO")
• HMAC-signed visitor Connection Cards — self-validating tokens (Base64Url + HMAC-SHA256) with 24-hour expiry, fuzzy email matching via Levenshtein distance with 20+ domain typo corrections
• Email broadcasts via Gmail SMTP, Mailchimp audience sync integration

Integrations & Mobile

• Bidirectional Planning Center sync — IAsyncEnumerable pagination with SemaphoreSlim rate limiting, HMAC-SHA256 webhook verification, remote_id bidirectional lookup
• React Native mobile app (iOS App Store + Android) — giving, check-in, small groups, watch sermons (YouTube), church info, biometric auth, multi-church selector, encrypted JWT via expo-secure-store
• Thermal printer integration — 4"x2" ZD421 labels (child, parent pickup, volunteer) with shared family security codes and auto-print on kiosk check-in
• Hierarchical group-based event auto-resolution — walks parent_group_id ancestor chain so children in nested groups auto-match department-level events
• Service plan builder with song library, chord charts with transposition, team scheduling, volunteer blockouts, and digital Music Stand module
• Two-tier profanity filter as global action filter — evasion-resistant regex with gap-matching, leetspeak detection, and 70+ word whitelist

Game Engine

• Single goroutine per table — all game mutations serialized on one goroutine; bots use the same action channel as humans
• Full state machine: WAITING → STARTING → PRE_FLOP → FLOP → TURN → RIVER → SHOWDOWN → HAND_OVER
• Side pot engine with correct all-in splitting — no spurious pots when bets are equal
• crypto/rand Fisher-Yates shuffle with rejection sampling — chi-squared validated across 10K hands
• Hand history persistence — hands, hand_players, hand_actions tables with retroactive evaluation for folded players
• 15-second auto-fold timer with pre-action queue bypass

Bot AI

• Three strategies: Passive (calls, folds to pressure), Aggressive (raises frequently, ~15% bluff rate), Balanced (position-aware, pot odds)
• AggroTracker — per-human raise frequency tracking; >40% raise rate (min 5 samples) triggers +15% bluff-catch boost
• Calibrated postFlopStrength rank map: HighCard=0.05 through RoyalFlush=1.0 with facingPressure fold thresholds
• Dynamic bot lifecycle — batch refill (15-50 hand lifespan), humans kick bots, 10s refill delay to prevent race conditions

Frontend & UX

• WSOP-style UI — adaptive racetrack geometry (2.2:1 aspect ratio), angular card placement per seat, bet badges on felt with gold chip icons
• Forced landscape rotation on mobile via CSS transform + useLandscapeDimensions hook
• Pre-action system — FOLD, CHECK, CALL ANY queueable during opponent turns, auto-fired with 300ms delay
• Expo web static export with cache-busting post-export scripts and service worker kill-switch
• Auto-auth (silent guest registration) + auto-sit + fixed shareable table IDs (/table/1, /table/micro, /table/high)
• Fully functional on mobile phone browsers — forced landscape rotation and adaptive geometry ensure playable UI on any screen size
• RNG stats dashboard — card frequency heat maps and hand rank distribution charts read directly from PostgreSQL

• JSON-driven content architecture — 6 data files decouple content from code, enabling updates without redeploys
• ~1.2 GB self-hosted media served directly (no CDN), with SiteGround Nginx proxy cache + PURGE on deploy
• Tiered .htaccess cache headers: no-cache for HTML/SW, 1-year hashed assets, 1-week PDFs, 1-year MP3s
• ErrorBoundary with stale-cache auto-recovery — detects chunk loading failures, performs one hard refresh + SW unregistration, prevents infinite loops via sessionStorage flag
• Embedded media player — YouTube embed conversion with timestamp parsing, inline MP3 playback, video lightbox modal
• Non-profit payment strategy — Stripe Payment Links (zero backend), ACH at 0.5% capped $5, Zelle zero-fee option
• Photo slideshow with lightbox navigation, keyboard controls, image preloading
• Responsive fluid typography with CSS clamp() and mobile-first sticky nav with scroll lock handling
• App-installable with web manifest, maskable icons, and standalone display mode
• Smart data sorting — pinned items (no date) first, then reverse-chronological dated items
• Fully functional on mobile phone browsers — responsive design with mobile hamburger nav and touch-optimized media playback

Role-Based Access

• Donor — View personal giving history, print end-of-year tax giving statements, and update contact information via Google OAuth login
• Viewer — Read-only access to donations, expenses, ledger (checkbook), and people data. Month-over-month and year-over-year financial trend reporting with interactive charts
• Admin — Full write access including auto-import from PayPal REST API, copy/paste bank data for automatic record creation and reconciliation, person merge, expense management, and bulk donor statement mailing

Reconciliation Engine

• Subset-sum matching algorithm with multiple strategies (by amount, by fee formula, by net amount) for penny-perfect multi-transfer PayPal batch matching
• 7-tier hierarchical name matching — alias lookup, exact match, fuzzy partial first/last, middle initial/nickname handling, and per-donor pattern scoring
• Bank web paste parser with type inference — classifies Credit, Debit Card, Zelle, ACH, Check from pasted bank data using keyword + fallback regex
• PayPal batch grouping by bank transfer events (not UTC dates) with estimated bank posting dates (+1 business day) and cross-day date correction
• Auto-reconciliation with 3-level confidence — exact/alias person match creates DB records tagged [auto-reconcile] with green AUTO badge
• Bank check duplicate prevention during reconciliation pass

Reporting & Analysis

• Excel export via ClosedXML: 10-sheet Ledger, 6-year Board Report, Checkbook Register, 990 Filing Data Export — matching original OHPM format exactly
• Board financial report with 3-year seasonal estimation — actual monthly weights replace linear extrapolation, with growth caps and ADP 3-pay-period anomaly handling
• Interleaved checkbook register — PostgreSQL ledger view merges donations and expenses chronologically with running balance from starting balance
• Per-donor historical pattern scoring — day-of-month statistical distributions (mean, stddev, z-score) across 3 years with ACH ±2 day / check ±5 day tolerance bands
• ADP payroll PDF parser with biweekly 3-pay-period detection, employer liability separation, and medical withholding income netting
• Fiscal year awareness throughout — every report endpoint accepts ?fiscalYear=N, 6-year range (actuals + estimate + projection)

Operations

• Gmail SMTP bulk mailing of annual donor giving statements with 2-second throttle, BCC tracking, and resume-capable statement_sends table
• 15-year historical data migration from Access VBA & Excel sources, dozens of legacy payees consolidated into unified people table
• Person merge UI with field-level override and duplicate detection — atomically reassigns all donations/expenses/users to target
• Multi-category vendor detection with auto-created "Pending" expense for inline breakdown that atomically replaces placeholder on submit
• Fully functional on mobile phone browsers — responsive top nav with hamburger menu and touch-friendly data entry

• Clean Architecture (Core, Infrastructure, Shared, API layers) with DI throughout
• Dual auth: hashed API keys for ingestion, JWT for dashboard — isolated auth paths per use case
• Cooldown-based alert deduplication — AlertConfig tracks LastFiredAt per event type with configurable cooldown windows to prevent alert spam
• Auto-triggered alerts on service restarts, down detection, and high CPU steal
• Gmail SMTP email delivery to managed recipient lists
• Bash watchdog collects system metrics (CPU, memory, swap, load, steal) and per-service stats (CPU, RSS, PID) via fire-and-forget POST
• HTTP health checks — curls each service endpoint, auto-restarts unresponsive services with graduated retry and escalation
• Self-monitoring: included in its own watchdog and nightly recycle rotation
• Composite indexed columns with descending order for efficient time-range queries — (server_id, recorded_at DESC)
• EF Core bulk update via ExecuteUpdateAsync() for non-materialized operations
• Multi-server ready with unique API keys per VPS and aggregate dashboard view
• Fully functional on mobile phone browsers — responsive dashboard with touch-friendly charts and status cards

• First-letter memorization algorithm with full edge-case handling: apostrophes, footnotes, leading quotes, Unicode normalization
• Server-side web scraping via AngleSharp with dynamic book abbreviation detection and robust footnote/cross-reference removal
• 10 Bible versions (CSB, ESV, LEB, LSB, NASB, NIV, NKJV, NLT, NRSV, RSV) with per-book chapter count validation
• Print-optimized dual-page layout — Aptos Serif 11pt, 60pt row heights, light blue (#BDD7EE) every 5th verse, matching original Excel formatting
• Special Psalm 119 acrostic heading support with verse association and section breaks
• In-memory caching with 24-hour TTL and typed response models
• Reusable public API endpoints with CORS for cross-project consumption
• Print CSS with page breaks, print-color-adjust: exact for background colors, and hidden UI controls