over-engineer
[email protected]

Konstantinos Pappas

Senior Software Engineer.

10+ years of experience designing and building web and mobile applications, from apps with 500K+ downloads to open source WordPress plugins powering 10K+ websites. Passionate about scalable architecture, maintainable and clean code, and long-term software quality.

See the workGitHubLinkedIn
Currently
Senior Software EngineerPressidium® · Mar 2021 – nowCo-founder & Software EngineerIcy Hippo G.P. · Jun 2025 – now
Full history
500K+ΠΑΛΕΡΜΟ downloads
10K+Sites using WordPress plugins I lead
10+ yrsShipping software
About

Hello, I’m Konstantinos.

Konstantinos Pappas

What I care most about is building systems that are reliable and easy to reason about, not just at launch, but a year later when requirements have shifted and the original author has moved on.

Most of my work sits in two places: developing and maintaining software at Pressidium, and iOS & Android apps at Icy Hippo, the company I co-founded. Outside of that: a home lab I keep self-hosting things on, and puzzle and board games.

Based inAthens, GreeceLanguagesGreek (native) · English (professional working proficiency)
Selected work

A few things worth mentioning

Apps, plugins, sites, and libraries out in the world, with real people using them.

ΠΑΛΕΡΜΟIcy Hippo G.P.2014 – now

A social deduction game 500K+ people installed

Cross-platform iOS/Android social deduction role-playing game built end-to-end in React Native. Organic growth, no publisher, years in the Greek App Store Top Paid charts.

React NativeJavaScriptExpo
Chillmate.appIcy Hippo G.P.2020 – now

Frictionless P2P group video calls

Browser-based collaboration platform on WebRTC and WebSockets: peer-to-peer video, chat, shared drawing and file transfer. Open a link, you are in.

WebRTCWebSocketsReactNode.jsJavaScriptFirebase
Pressidium Cookie ConsentPressidium®2023 – now

GDPR consent solution with 10,000+ active installations

Open source WordPress plugin with Google Consent Mode v2, consent logging, automatic script blocking and multilingual support. I own releases, reviews and direction.

WordPressPHPReactJavaScript
Pressidium PerformancePressidium®2026 – now

One click between a site and better Core Web Vitals

Open source optimization plugin: image optimization, CSS and JS minification, and the unglamorous fixes that move real Lighthouse numbers.

WordPressPHPReactJavaScript
Inverted CornersPersonal project2021

A CSS Houdini paint worklet for impossible corners

Renders complex corner shapes, gradients and masks from almost no markup. Built to find out where the experimental Houdini APIs stop.

CSS Paint APIJavaScript
Exchange RatesPersonal project2019–2021

1,500 weekly downloads of a very small library

Node.js wrapper for fixer.io-compatible APIs, resolving European Central Bank rates. Small surface, boring API, still installed every week.

Node.jsnpmJavaScript
Link Verification for MastodonPersonal project2022 – now

Proving you own your site on the fediverse

Lightweight WordPress plugin that injects the required rel="me" link tag into your site’s head, so ownership verification on Mastodon takes a click instead of a code snippet.

WordPressPHPMastodon
AnimentorPersonal project2020

Lottie animations as a drag-and-drop Elementor widget

Bridges Lottie and the Elementor page builder: what previously needed custom code became a widget wired into the Media Library, with full playback controls in the Elementor panel.

WordPressPHPElementorLottie
Experience

What I’ve been up to

Ten years across WordPress infrastructure, SaaS platforms and iOS & Android apps.

Senior Software EngineerPressidium® — TechIO Limited · London, UK · RemoteMar 2021 – now
  • Technical owner of a business-critical WordPress mu-plugin handling caching, CDN integration and platform functionality across thousands of client sites.
  • Lead development of open source WordPress plugins powering 10K+ websites — releases, architecture, code review and product direction.
  • Frontend and backend optimization work that moved Google Lighthouse scores from 56 to 98.
  • Expanded automated coverage with PHPUnit, Mockery and Cypress; fewer regressions, calmer deploys.
  • Improved workflows with GitHub Actions, GitLab pipelines, PHPCS, PHPStan, PHPMD and ESLint.
Co-founder & Software EngineerIcy Hippo G.P. · Ilioupoli, GR · Part-timeJun 2025 – now
  • Co-founded a software company around consumer apps and real-time communication, leading product architecture and long-term technical direction.
  • Built and still lead Palermo, one of Greece’s most popular social deduction games — 500K+ organic downloads, no publisher.
  • Developing Chillmate.app: WebRTC and WebSocket peer-to-peer calls, chat, collaborative drawing and file sharing in the browser.
  • Own production infrastructure, CI/CD, deployments, monitoring and analytics across web and mobile.
Software EngineerSatiSupp Hellas · Chalandri, GR · On-siteMar 2017 – Feb 2021
  • Designed and built SaaS products, membership platforms and multisite e-commerce on WordPress.
  • Led full-stack architecture and end-to-end delivery across several production systems.
  • Cut repetitive operational work with Slack bots, Google Sheets add-ons, React apps and Python scripts.
  • Built APIs against Amazon Marketplace Web Services for order tracking and stock sync across marketplaces.
Stack

Tools I reach for

PHPPythonReactWebRTCFirebaseDockerGitE2E testing
JavaScriptWordPressReact NativeWebSocketsRedisCI/CDCSS
TypeScriptNode.jsExpoREST APIsSQL / NoSQLBashUnit testing