Declan L

Self-taught full-stack developer with 12+ years of continuous hands-on experience, writing production code since 2013 at age 15. Builds and ships complete web applications end to end — Next.js/React front ends, Python/FastAPI back ends, MySQL data layers, and Linux infrastructure on AWS behind Nginx and Cloudflare. Currently the sole developer and operator of decint.tools, a live security-tooling SaaS with paying customers, covering architecture, implementation, deployment, security, and support.

Strong secondary depth in networking, systems security, and OSINT engineering.

Self-Employed at DECINT Tools (2013-01 – Present)

Built and operate decint.tools solo — a production SaaS platform with paying customers, owning the entire stack from the Next.js 14 front end through the FastAPI service layer, MySQL schema, and Linux deployment.

• Designed an async API aggregation layer in FastAPI that fans out to seven third-party intelligence providers, normalizing every response to a single schema with per-provider circuit breakers, TTL-based MySQL caching, and graceful degradation when upstreams fail.
• Re-architected authentication to passwordless — migrated the platform to passkeys (WebAuthn) with GitHub and Google OAuth, retired legacy key-based login and TOTP, hard-blocked privileged setup routes, and built a username reservation system with leet-speak normalization to block impersonation.
• Runs production infrastructure on AWS EC2 (Ubuntu) behind Nginx and Cloudflare: TLS via origin certificates, systemd units scoped with least-privilege Linux capabilities, PHP-FPM admin tooling, plus deployment, monitoring, and incident response.
• Architected a licensing and payments backend on Cloudflare Workers + D1 + Stripe issuing time-bound license keys (1–24 months) with hardware binding and PyArmor obfuscation for commercially distributed desktop tools.
• Shipped a packaged desktop application (DECINT VISAGE) in Python with MediaPipe and PyInstaller, implementing One Euro filtering, Schmitt-trigger state detection, PERCLOS metrics, and Welch-averaged spectral analysis with statistically derived confidence intervals.
• Delivered a catalogue of Python network tools — a GUI packet sniffer with PCAP/CSV/JSON export, a LAN monitor writing SHA-256 chain-linked tamper-evident logs, IP-camera discovery via ONVIF/RTSP fingerprinting with nmap integration, and a Tor-routed search engine with a JSON endpoint registry, stream isolation, and relevance scoring.
• Early years (2013–2019): self-taught from age 15, progressing from static HTML/CSS/JavaScript sites to PHP/MySQL database-backed applications and self-managed Linux servers — the foundation for every project since.

Site Work at Uniform Developments, HN Homes, Claridge Homes (2019-01 – 2024-12)

Site work across three residential builders alongside continuous self-directed development; developed the schedule discipline, spec-reading precision, and client-facing communication now applied to software delivery.

Certificate in Home Inspection – Algonquin College

Technical Study in Python, Linux systems, networking, web development, and application security – Self-Directed (2013-01)