🏆 Over 100 graduates · Sold out in Singapore, Athens, London

From Lizard to Wizard

The system design intensive that turns mid engineers into senior ones.

299€

4-hour intensive · Limited seats

Next session · Thursday, May 28 · Limited seats

Thursday, May 28.
Limited seats — grab yours fast.

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4 hours · Thursday May 28 · 5–9 PM CET, Remote

The curriculum

Five parts. One system-design intensive. Every part comes with a working demo we walk through together.

PART 01 · OF 05

Frontend System Design

Build a WhatsApp-scale chat app the way senior engineers do — then walk into your next system-design interview ready to defend every choice out loud.

WHAT WE'LL EXPLORE

  • The RADIO framework — 5 minutes that turn an interview from "panic mode" into a structured walkthrough
  • Architecting a real-time chat app: virtualization, optimistic updates, WebSocket reconnection, typing indicators, offline queue
  • Folder structure that scales — feature-based vs atomic, when to switch
  • State management decision tree — useState, Context, React Query, Zustand, when each one is right
  • Cursor-based pagination + scroll-position management (the edge cases interviewers love to ask)
  • Normalized state shapes so the same message never lives in two places

🎮 We'll walk through a working demo together. You take home the full code.

I'm convinced — save my seat →

PART 02 · OF 05

Microfrontends & Module Federation

Why every 30+ engineer org you've heard of ended up here — and how to adopt them without accidentally building a distributed monolith.

WHAT WE'LL EXPLORE

  • The 4 real reasons companies adopt microfrontends
  • Vertical vs horizontal architecture — which one to pick for your team's shape
  • Module Federation deep-dive — dependency sharing, runtime loading, shared singletons
  • Inter-microfrontend communication: query params, broadcast API, shared event bus, "brain" microfrontend
  • Bounded contexts + Conway's Law applied to frontend org charts
  • The smell that means microfrontends are wrong for your situation (recognize it before you commit)

🎮 We'll walk through a working demo together. You take home the full code.

I'm convinced — save my seat →

PART 03 · OF 05

BFF & Server-Driven UI

Move UI decisions to the backend so iOS, Android, and web stay in sync without three deploy cycles and an App Store review.

WHAT WE'LL EXPLORE

  • Server-driven UI: when the backend shapes what users see
  • Designing the render contract between server and client
  • Driving navigation, analytics, and A/B tests from the backend
  • The line between SDUI and "downloading code" — Apple and Google's rules
  • Backend-for-Frontend: when a tailored gateway pays for itself
  • Live config updates without WebSocket complexity

🎮 We'll walk through a working demo together. You take home the full code.

I'm convinced — save my seat →

PART 04 · OF 05

Event-Driven Architecture

Stop tangling your components together — let them talk through events you can replay, audit, and test in isolation.

WHAT WE'LL EXPLORE

  • The event bus pattern — when it saves you, when it betrays you
  • Decoupling cross-cutting concerns (notifications, analytics, audit trails) from business logic
  • Pub/Sub for inter-microfrontend communication without a global store
  • Frontend event sourcing — yes, really, and when it's the right call
  • Replayability + time-travel debugging from your event log
  • Avoiding the "spaghetti events" anti-pattern with named domains and contracts
  • Testing event-driven flows without mocking the entire universe

🎮 We'll walk through a working demo together. You take home the full code.

I'm convinced — save my seat →

PART 05 · OF 05

Frontend Observability

Stop guessing what your users hit. Logs, traces, metrics — and dashboards that surface incidents before your customers tweet about them.

WHAT WE'LL EXPLORE

  • Logs vs metrics vs traces — what each one is actually for, and why mixing them costs you
  • Instrumenting a frontend with OpenTelemetry end to end
  • SLOs and SLIs that don't page on noise
  • Distributed tracing across microfrontends — yes, this is hard, here's how
  • Real-user monitoring (RUM) vs synthetic monitoring — both, neither, when
  • Walking through a real production incident together — what we'd have caught earlier
  • Alert rules engineers actually trust (the absence of "alert fatigue" is a metric)

🎮 We'll walk through a working demo together. You take home the full code.

I'm convinced — save my seat →
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One session, limited seats. Filling up fast — lock yours in before it's gone.

📅 NEXT & ONLY SESSION

  • 5:00 PM – 9:00 PM Barcelona time
    Auto-converted to your local time at signup
  • Fully remote — join from anywhere
  • 4-hour intensive — limited seats, once filled it's gone
  • €299 — full workshop, all bonuses included
Save your seat — €299 →

📋 NEED TO CONVINCE YOUR BOSS?

Build your pitch in 60 seconds

Pick the curriculum topics your role cares about, fill in your details, and we generate a tailored email — ready to send straight to your manager's inbox.

💰 ROI BREAKDOWN

  • Travel costs€0
  • Hotel nights€0
  • Workshop fee€299
  • TOTAL€299

vs. equivalent conference: €2,000+ + travel + hotel

🎯 PICK WHAT MATTERS

  • ☑ Frontend System Design
  • ☐ Microfrontends
  • ☑ BFF & Server-Driven UI
  • ☐ Event-Driven Architecture
  • ☑ Observability

→ Builds a tailored email your manager actually wants to read

💬 "The workshop pays for itself the first time it prevents one bad architecture decision. Everything after that is profit."
Open the pitch builder →

You will level up

  • Pass frontend system design interviews with structured, defensible answers
  • Architect production-grade React systems that scale past 100k users
  • Decide between microfrontends, BFF, and SDUI based on your team's actual shape
  • Instrument a frontend with observability that surfaces incidents before customers do
  • Defend architectural choices out loud — to your team, your manager, and your interviewer

Prerequisites

  • 2+ years JavaScript/TypeScript
  • Familiarity with React
  • Basic data structures
  • Experience with REST APIs
  • Working knowledge of Git

Not for beginners.

Ready to level up?

Yes, count me in →

4-hour intensive · Thursday May 28 · 5–9 PM CET Remote

299€

⏰ Limited seats · Thursday, May 28, 2026 — once it's full, that's it.

Save my seat →

You also get

Everything else included with your seat — no upsells.

Full workshop repo

Every line of code we write together, yours to keep and revisit.

All slides, every project

The complete deck for every part — perfect reference material.

Discount on future workshops

A standing discount on anything I teach next.

Accessibility deep-dive deck

Bonus slides on WCAG, ARIA, and inclusive design — yours to keep.

Security essentials deck

Bonus slides on XSS, CSRF, CSP, and auth patterns — yours to keep.

Design patterns deck

Bonus slides on creational, structural, and behavioral patterns in React.

Note: This workshop is the system design deep-dive. Patterns, Testing, Security, and Accessibility get their own focused workshops in the future — drop your email in the newsletter to hear when they open.

What attendees say

"Before this workshop, system design interviews were a black box for me. Dan walked us through designing a WhatsApp-scale messaging system step by step — from choosing between polling and WebSockets, to sharding strategies, to handling eventual consistency. I used exactly that framework in my interview at a FAANG company two weeks later and got the offer. The way he breaks down trade-offs between approaches made everything click."

Workshop attendee Senior Engineer · Singapore

"I've been a frontend developer for 4 years and never felt confident discussing architecture beyond my React components. The system design module changed that completely. We designed a real-time notification system, debated CAP theorem trade-offs, and Dan pushed us to defend our decisions out loud. That practice of articulating technical reasoning was the most valuable part. I also didn't expect the security section to be so hands-on — we actually exploited XSS vulnerabilities live."

Workshop attendee Frontend Developer · Athens

"What sets this apart from online courses is that Dan doesn't just teach — he challenges you to think. During the system design exercises, he'd throw curveballs: 'What happens when this service goes down?' or 'Your database just hit 10TB, now what?' That pressure to think on your feet is exactly what interviews feel like, and you can't get that from a YouTube video. I walked out feeling like I'd leveled up from mid to senior in how I reason about systems."

Workshop attendee Full-stack Developer · London

Still weighing this against alternatives?

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Your Instructor

Neciu Dan

Dan Neciu

Staff Engineer · Tech Co-Founder · International Speaker

Dan has spent 12+ years shipping production systems at scale — from Glovo's delivery platform serving millions of orders, to AdoreMe's e-commerce frontend, to building CareerOS from the ground up as technical co-founder and staff engineer. He improved Glovo's Web Core Vitals from 50% to 90% green, architected CI/CD pipelines for 4 frontend applications, and led the integration of Sales, Product, and Engineering at CareerOS.

14+ years of engineering
6 Programming Languages mastered
26 speaker events
  • Staff Software Engineer — led teams across CareerOS, Glovo, AdoreMe
  • Speaker at React Alicante, Techorama Belgium, Utah JS, Frontmania Netherlands
  • Host of Señors @ Scale podcast — interviewing senior engineering leaders
  • Organizer of ReactJS Barcelona meetup (2000+ members)

Helping engineers level up from mid to senior and beyond

Built products at

Glovo CareerOS AdoreMe
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