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Operational · Colombo, Sri LankaManager of Sustainability & System Administration @ Connaissance De Ceylan

Architecting mission-critical travel operations, developer telemetry, and interaction systems.

I’m Dulaj Mendis. I design and engineer enterprise-scale software where database integrity, mathematical honesty, and sub-100ms micro-interactions converge.

Verified Architecture & Craft

Lead creator of Travex (the 84,000-line production itinerary studio and DMC operating system powering real tour operations for CDC & TDC), PulseGuard (developer observability cockpit), and the Sri Lanka Railway transit network (422 stops across 1,444 km at railway.dulajmendis.com). Recognized by The Browser Company as an Arc "Nimble Perfectionist".

Core Stack:NestJS & Node.js·React 19 & Next.js 16·PostgreSQL & Prisma 6·Redis & Docker·Tailwind CSS·GIS & Leaflet
Verifiable Operational Telemetry

Production scale measured in real code and systems

Source-of-truth: Verified workspace audit
Verified System
58 Models · 237 Endpoints
Production Architecture
Active Stack
~84,000 LOC
Authored Codebase
Live Subdomain
422 Stops · 1,444 km
Railway Network GIS
Telemetry
99.98%
Observability SLA
Core Tenet
0.00%
Fabricated Metrics
Selected Systems Architecture

Battle-tested production systems, not boilerplate demos.

Every project listed here is derived from verified codebase repositories, database schemas, and live operational deployments.

Enterprise Travel Operations & Logistics
Live Enterprise System

Travex

Production DMC Operating System & Itinerary Studio · 2024 – Present (Live in Production)

Travex is a comprehensive travel-operations platform designed and built from the ground up for Connaissance De Ceylan (CDC) and its TDC brand. It combines day-by-day tour authoring, immutable snapshot versioning, automated multi-currency pricing, and dual-brand document generation across English, French, and Spanish.

Dual-Brand Document Output:
58
Database Models
237
API Endpoints
~84,000
Codebase Scale
~100
Test Suites
Key Architectural Milestones
  • ▸Immutable snapshot engine: Deep-copy version tree with DMMF drift-guard tests and payload-replay undo.
  • ▸Document Generation Engine: Programmatic DOCX synthesis converted to PDF via LibreOffice headless, verified for web-preview visual parity.
  • ▸Margin & Cost Engine: Pure static resolvers with an honest null-over-wrong convention (no silent pricing guesses).
NestJS 10Prisma 6PostgreSQLRedisReact 19ViteTailwind CSS v4+4 more
Developer Tooling & Infrastructure
Developer Cockpit

PulseGuard

Unified Developer Observability Platform · 2026

PulseGuard eliminates developer tool sprawl by replacing fragmented monitoring subscriptions with one unified, zero-overhead cockpit. It features instant crontab heartbeat monitoring, synthetic multi-region HTTP/API health checks, SSL certificate chain expiry warnings, and hosted public status pages.

1-Line Dead Man's Switch
curl -fsS --retry 3 https://api.pulseguard.dev/ping/...
99.98%
Uptime Target
15s
Setup Time
3 Tools
Free Utilities
Multi-Sync
Alert Channels
Key Architectural Milestones
  • ▸Zero-agent curl telemetry: Scheduled jobs ping a unique monitor UUID with exit status and execution duration.
  • ▸Synthetic HTTP inspection: Automated background ping engine triggered via serverless Edge and GitHub Actions workflows.
  • ▸Proactive TLS audit: Deep TLS handshake inspection extracting issuer chain and exact expiration timestamps.
Next.js 16 (App Router)React 19TypeScriptTailwind CSSLucide ReactGitHub Actions CronVercel Edge Functions
Repository
Geographic Information Systems & Public Transit
Transit Telemetry

Sri Lanka Railway Network

Canonical Dataset & Interactive GIS Transit System · 2026

A meticulously calibrated GIS data pipeline and interactive Leaflet map representing the complete Sri Lanka Railways network. Built with Douglas-Peucker simplified geometry, a topological travel-time graph model, bilingual English/Sinhala search, elevation profiles, and an offline-first PWA shell.

Subdomain: railway.dulajmendis.com100% Offline PWA
422
Stops Mapped
1,444 km
Track Chainage
10 Lines
Railway Lines
100% PWA
Offline Shell
Key Architectural Milestones
  • ▸Deterministic 12-step data pipeline: From vision tiles to Wikipedia scraping, Wikidata multilingual labels, and OSM way tracing.
  • ▸Topological Speed & Dwell Model: Calibrated against real-world runs (Fort to Kandy ≈ 3h, Kandy to Ella ≈ 6.5h) with line-change transfer penalties.
  • ▸OKLCH Color Science: High-contrast line palette tuned specifically for light and dark basemaps maintaining perceptual uniformity.
Leaflet GISVanilla ES ModulesOKLCH PaletteOpenStreetMap OverpassPWA Service WorkersDouglas-Peucker SimplificationNginx Vhost
Live Application
Eco-Tourism & Hospitality Operations
Commerce & Ops Engine

Experience Udawalawe & Ceylon 1850

Sustainable Hospitality & Travel-Commerce Platform · 2025 – Present

A bespoke travel-commerce platform and operations back-office for Experience Udawalawe (safaris and village immersion) and the dining brand Ceylon 1850. Built with strict data integrity rules: no artificial urgency counters, zero floating-point math, and guarded booking state transitions.

11
Bounded Modules
Integer Kernel
Monetary Math
Strict Non-Fake
Honesty Standard
Filament v5
Ops Back-Office
Key Architectural Milestones
  • ▸Domain-driven modular kernel: Modules communicate exclusively via typed Actions and domain events.
  • ▸Guarded Finite State Machine: Booking state transitions adhere to strict validation rules preventing race conditions.
  • ▸Idempotency middleware: Prevents double-booking and duplicate payment submissions during transient network failures.
Laravel 13PHP 8.4+Filament v5Inertia.js v2React 19TypeScriptTailwind CSS v4+2 more
Data Engineering & Market Intelligence
Telemetry Pipeline

Personal Intelligence OS

Automated Macroeconomic & Tourism Telemetry · 2025 – 2026

A self-hosted intelligence stack orchestrating automated market data collectors, macroeconomic indicators (FRED, yfinance, pytrends), and tourism arrivals telemetry. Produces automated weekly command briefs and threshold alerts via Anthropic API synthesis.

6 Collectors
Collectors
Asia/Colombo
Timezone
PostgreSQL 16
Database
Docker Compose
Orchestration
Key Architectural Milestones
  • ▸Idempotent upsert collectors with composite primary keys preventing duplicate historical records.
  • ▸Two execution contexts sharing codebase mounts between host virtual environment and Docker runtime.
  • ▸LLM synthesis engine generating automated executive briefings from quantitative database snapshots.
PostgreSQL 16PythonStreamlitn8nDocker ComposeNginx Proxy ManagerAnthropic API
Decision Intelligence & Automotive Engineering
Decision Engine

Automotive Intelligence Workspace

Algorithmic Vehicle Inspection & Risk Scoring · 2025 – 2026

A specialized inspection and risk-evaluation framework for high-value vehicle acquisitions. Features hard structural elimination gates, automated market scraping across local portals, and a 100-point engineering scoring algorithm prioritizing long-term reliability and parts availability.

100 Points
Scoring Scale
Hard Stops
Elimination Gates
Multi-Portal
Scanners
Key Architectural Milestones
  • ▸Binary elimination gates that immediately abort analysis if flood damage or chassis defects are detected.
  • ▸Weighted scoring system calibrated to Sri Lankan parts supply and workshop specializations.
Python (Stdlib)CLI IntelligenceMarkdown Knowledge BaseDeterministic Scoring Engine
Interactive UX Engineering Lab

Interaction systems engineered for the Doherty threshold.

Based directly on my documented design systems catalog: right-click mechanics, collision-aware geometry, optimistic UI latency budgets, and predictable filter algebra.

Rule 01: Context Menu Architecture

Never render before measuring fit. If the cursor approaches the bottom or right boundary of the viewport, the menu flips upward or leftward so it never clips offscreen.

Engineered Specifications:
• Measure, then place dynamically
• Group by intent (Primary, Edit, Danger)
• Isolate destructive action last in red
• Esc dismisses cleanly
Right-Click or Long-Press anywhere in this arena

Try clicking near the edges or bottom corners to watch the collision-aware flipping engine in action.

Systems Ethos & Core Mantras

Principles refined under operational production pressure.

I do not believe in synthetic complexity or superficial metrics. High-performing software is built on mathematical honesty, immutable state snapshots, and empathetic human workflows.

The Browser Company Milestone17 Feb 2024

Arc Browser: Nimble Perfectionist

Awarded during Arc's 1-year anniversary for relentless dedication to interaction precision, ergonomic tab workflows, and finding edge cases where microseconds matter.

100%
CRAFT STANDARD
No compromise on polish
Principle 01Travex Margin Engine & Experience Udawalawe Core Policy

Honest Data Over Silent Guesses

"Null over wrong. Never fabricate scarcity, dates, or prices."

If a supplier cost, exchange rate, or availability slot is unverified, systems must yield an explicit unconfirmed state rather than interpolating plausible fakes. Trust is irreversible once lost.

Implementation: Strict TypeScript nullability, explicit REQUIRES_CONFIRMATION domain states, and zero fake review widgets.
Principle 02Travex DMC Operating System

The Version is the Source of Truth

"Service orders, invoices, and schedules derive from confirmed snapshots."

Downstream operations (vouchers, driver sheets, rooming lists, client invoices) must strictly branch from an immutable version snapshot, ensuring what was sold is identical to what is operated.

Implementation: Deep-copy snapshot engines, DMMF drift-guard tests, and deterministic DOCX-to-PDF compilation.
Principle 03EvaraOS & Multi-Brand Travex Blueprint

One Codebase, Per-Tenant Instances, Never Fork

"White-labeling belongs in configuration tokens, not source branches."

Branching codebases per client is a maintenance death spiral. Brand differentiators must live in brand token registries, while feature divergence is flag-gated on a single verified release train.

Implementation: Strict database tenant walls with 404-not-403 security semantics to avoid tenant reconnaissance.
Principle 04Railway GIS Deploy Runbook & CI Pipeline

HTTP 200 is Not Proof of Success

"Assert content types, payload integrity, and DOM rendering."

A misconfigured Nginx vhost can return HTTP 200 while wiping MIME types, causing browsers to download HTML as binary streams. True health checks verify response headers and content bodies.

Implementation: Automated curl assertions on content-type headers, bundle hashes, and headless DOM readiness.
Verified Professional Roles & Advisory

Operational leadership grounded in real business outcomes.

Balancing enterprise systems administration, software architecture, and advisory oversight across luxury hospitality and tourism.

Manager of Sustainability & System Administration

Full-Time Leadership
Connaissance De Ceylan (CDC)
Current Role·Colombo, Sri Lanka

Directing enterprise systems infrastructure and sustainability initiatives for one of Sri Lanka’s premier destination management companies. Designed, engineered, and shipped Travex—the company’s primary operations platform.

Verified Responsibilities & Milestones:
  • Architected and implemented Travex, the 84,000-line production itinerary studio and DMC operating system serving CDC and TDC brands.
  • Transformed proposal workflows: reduced luxury custom tour turnaround from 4+ hours to minutes with automated DOCX and PDF document synthesis.
  • Supervise operational database integrity (PostgreSQL, Prisma, Redis) across multi-department tour booking, fleet allocation, and pricing workflows.
  • Lead sustainability technology programs and digital transformation strategies to eliminate paper waste and modernize legacy processes.
NestJSPrismaPostgreSQLRedisReact 19Tailwind CSSCloudflare R2DockerLinux / VPS

Advisory Systems Partner & Operating Technologist

Advisory Partner
Experience Udawalawe · Ceylon 1850 · Owen Rich
2025 – Present·Godakawela & Udawalawe, Sri Lanka

Providing strategic operating systems, digital infrastructure, and marketing architecture for three linked hospitality and eco-tourism enterprises in southern Sri Lanka.

Verified Responsibilities & Milestones:
  • Architected the owner-owned travel-commerce and booking back-office platform using Laravel 13, Filament v5, and Inertia.js React.
  • Enforced strict "honest data" policies: eliminating deceptive scarcity countdowns, zero float currency math, and explicit confirmation states.
  • Structured operational data models bridging hotel accommodation (Owen Rich), destination dining (Ceylon 1850), and guided safari excursions.
  • Defined guest communication channels, local licensing workflows, and supplier coordination systems.
Laravel 13Filament v5Inertia.jsReact 19MySQLTailwind CSSOperations Modeling

Nimble Perfectionist Recognition

Global Recognition
The Browser Company
17 Feb 2024·New York / Global

Recognized for relentless attention to craft, interaction precision, and early power-user product feedback during the Arc Browser 1-year anniversary milestone.

Verified Responsibilities & Milestones:
  • Acknowledged for deep feedback on interaction engineering, tab ergonomics, and keyboard-first productivity workflows.
  • Embodied the "Nimble Perfectionist" design philosophy: obsessing over microseconds of response time and layout stability.
Interaction DesignErgonomicsUX EngineeringKeyboard-First Workflows
Direct Dispatch & Inquiries

Initiate a conversation or systems review.

Open to technical advisory, enterprise systems consultation, and high-impact software engineering challenges.

Operational Status

LocationColombo, Sri Lanka
Local WindowActive · Colombo (UTC+5:30)
Direct GitHub@DulajMendis
Inquiries are received directly into monitored notification queues. No third-party tracking scripts or spam harvesters are employed.
Privacy & Data Policy

Your contact details are used strictly for direct professional communication. No marketing lists, trackers, or automated cold outreach.

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