Lead frontend developer specializing in modernizing legacy systems into scalable, maintainable UI architectures. I've rebuilt enterprise platforms from Ext.NET to React and shipped modular Angular systems from the ground up.
Currently leading frontend on ClearSkies at Odyssey Cybersecurity, owning architecture direction, mentoring the team, and driving a full platform rewrite. I optimize for code that outlives the sprint: clear module boundaries, reviewable patterns, and UIs other engineers can extend without a walkthrough.
Own frontend architecture for ClearSkies: module boundaries, shared patterns, and long-term React platform direction. Lead a small frontend team through mentoring, structured code reviews, and unblocking delivery while raising the quality bar.
Core contributor to the ClearSkies rewrite from C#/Ext.NET to React. Shipped composable component systems that replaced a brittle legacy UI layer, reducing developer onboarding friction and improving cross-team maintainability across the platform.
Owned frontend delivery on an internal staffing platform for three years: shipped the original scheduling module in Angular/TypeScript, then kept building calendar-heavy features on top, including an automatic shift-to-staff assignment engine. Wrote unit tests throughout and, with no dedicated designer on the team, owned UI design decisions directly, iterating 2-3 directions per feature before committing.
Built and maintained a custom e-commerce platform end-to-end: product pages, landing flows, and conversion-optimized checkout. Owned the frontend layer alongside inventory systems and pricing logic. Business strategy and social channel growth drove recurring brand partnerships.
Shipped full-stack AI product: drop an X handle and get a generated, shareable business card. Angular 19 frontend, Express + MongoDB backend with response caching to control API spend, an OpenAI prompt pipeline, and a screenshot share-to-X flow. 120+ cards generated in the wild.
Parking marketplace PWA built for the Bank of Cyprus Fintech Hackathon: live map with geolocation, booking flow, QR check-in, realtime payment events over WebSockets, push notifications, and a vendor dashboard, end to end against a deployed backend.
On-prem CLI daemon that watches git repositories for risky changes: SQL migrations, OpenAPI contract diffs, sensitive paths, and posts prioritized Slack digests. SQLite-backed state, Dockerized, covered by vitest suites. No code ever leaves the network.
React form component library: 15+ composable, typed field components behind a single declarative API, shipped with a docs site featuring live previews, copyable examples, and a visual form builder.
Not a blog. Every non-obvious call I've made on a real project, written up the way I'd write it for a team: the constraint, the options I rejected, what the choice cost me, and what I'd do differently. The mistakes are in here too — they're the useful part.
Work in progress, listed honestly. Source is public from day one; nothing here claims to be finished.
Personal finance app that imports bank transactions and surfaces spending patterns before money leaks.
Next //Budget rules engine and intent-based spending alerts.
Let creators collect testimonials, customize an embeddable widget, and publish a public review page.
Next //Billing, onboarding polish, and embed script for third-party sites.
Live market-watch dashboard for trading/forex platforms — streaming price data, not a static demo.
Next //Virtualized order book that holds 60fps under load, profiled and written up, plus P&L math tests.
+ more experiments on github.com/lefkosp ↗