Michael Cullen

Technical Lead · Architect · Hands-On Engineer

requests@mdc.tf East Midlands, UK https://mdc.tf

How I Work

I typically act as the senior technical owner for the systems I’m responsible for: shaping architecture and direction with stakeholders, planning and sequencing work, and still doing the low-level engineering when the problem is too awkward or specialised to hand off.

Discover

Map the real system: what exists, how it talks to everything else, who owns what, and where it’s brittle. Identify quick stabilising changes and surface hidden risk.

Stabilise

Fix critical issues, harden infrastructure, remove single points of failure, and automate repetitive work so the team can focus on changes that matter.

Evolve

Introduce new architectures, tooling, or process only where the return is clear. Keep what’s stable, modernise what isn’t, and ensure changes remain understandable, observable, and reversible.

Experience & Projects

Infrastructure, Security & Technical Leadership
Mar 2022 – Present · Remote

24/7 incident response, reverse-engineering upstream binaries to identify vulnerabilities, building in-house mitigation and monitoring, and automating large-scale operations for a high-traffic online platform. Often acting as the senior technical decision-maker while remaining hands-on.

Tech used: C#, scripting (PowerShell/Bash), Windows Server, Linux, reverse-engineering tooling (IDA Pro, Ghidra), custom automation, monitoring and log aggregation.

Custom Social Platform Development
Architecture & Implementation

Designed and delivered a photo-focused social platform: custom PHP/MySQL backend, real-time WebSocket notifications, Redis queues, admin tooling, and a responsive UI. Full lifecycle ownership from initial data model and UX through deployment and iteration.

Tech used: PHP, MySQL/MariaDB, Redis, JavaScript/TypeScript, WebSockets, JSON, REST APIs, Linux, Nginx/Apache, Docker, CI/CD, Cloudflare for edge and DNS.

Game Server Development & Tooling
Backend Systems & Formats

Built server-side extensions, asset/script tooling, and administrative systems for large multiplayer environments. Extensive work with undocumented binary formats, network protocols, and reverse-engineered APIs.

Tech used: Enforce Script, C#, C/C++-style patterns, binary parsers, custom file formats, protocol inspection, SQL-backed services, scripting around deployment and diagnostics.

Voting & Realtime Systems
Cloudflare Workers / Durable Objects

Designed and implemented distributed, strongly consistent realtime backends on serverless platforms. Focused on correctness under concurrency, low-latency delivery, sharded state, and failure handling.

Tech used: Cloudflare Workers, Durable Objects, TypeScript/JavaScript, JSON, WebSockets, REST APIs, Redis, D1/SQL-style storage, event-driven patterns, observability and tracing.

Systems Administration & On-Prem Infrastructure
Windows Server Environments

Planning, deployment, and maintenance of traditional on-prem estates: Active Directory, Group Policy, DNS/DHCP, RRAS, VPN, RDP access, file services, and legacy migrations. Frequently brought in to untangle inherited, partially-documented setups.

Tech used: Windows Server, Active Directory, Group Policy, DNS, DHCP, RRAS, VPN (remote access and site-to-site), RDP, IIS, certificate services, backup and DR tooling.

Clients & Collaborations

Online Gaming Infrastructure
Security & Operations

Long-term engagement providing infrastructure, automation, and incident response support for a large online gaming community with continuous live operations.

Publishing & Digital Media
Content & Subscription Platforms

Work with publication-focused clients on content workflows, paywalled sections, user account flows, and integrations between CMS platforms, billing, and reporting.

Logistics & Supply Chain
Operations & Systems Integration

Experience supporting and integrating systems used by large logistics providers (including courier networks on the scale of DHL), with work touching tracking, reporting, and operational tooling.

Service & Booking Platforms
SMEs & Online Services

Design and implementation of bespoke service websites and internal tools: booking systems, simple CRMs, integrations with payment providers, and automation around routine customer communication.

Independent Developers & Teams
Legacy & Integration Consulting

Ad-hoc consulting for small teams and individual developers: modernising legacy applications, integrating awkward third-party components, and simplifying fragile one-off hosting setups.

Experience & Tools Overview

Languages & Backends

Enforce Script, C#, PHP, TypeScript/JavaScript, SQL (PostgreSQL, MySQL/MariaDB), VB/ASP Classic; working knowledge of C/C++, Python, Pascal/Delphi, Go, Bash — used across social platforms, realtime systems, admin tooling, and game backends.

Data, APIs & Integration

JSON, XML, CSV, YAML; REST APIs, Webhooks, WebSocket APIs, queues; schema design and migration; ETL-style pipelines between legacy on-prem systems and modern services — applied in publishing, logistics, and bespoke service platforms.

Infrastructure & Networking

Windows Server, Linux (Debian/Ubuntu), Active Directory, Group Policy, DNS, DHCP, RRAS, VPN, RDP, IIS, Nginx, Apache, reverse proxies, SSL/TLS termination, load balancing — used to keep mixed estates running while planning and executing modernisation.

Cloud & Serverless

Cloudflare Workers & Durable Objects, Cloudflare Pages, Redis, Docker, Git-based deployment, CI/CD pipelines, and pragmatic AWS usage (EC2, S3, RDS-style services) — primarily for realtime and event-driven workloads.

Operations, Security & Reverse Engineering

Git, shell tooling, log aggregation, metrics/dashboards, backup and DR planning, plus reverse-engineering (IDA Pro, Ghidra, binary analysis, protocol inspection) and hardening of public-facing services — used heavily in long-running online platforms and bespoke game ecosystems.

Contact

For consulting, interim technical leadership, or full-time roles, reach me at:
requests@mdc.tf