πŸ† Over 100 graduates Β· Sold out in Singapore, Athens, London

From Lizard to Wizard

Master algorithms, system design, and engineering thinking in one intensive 4-hour session

250€

4-hour intensive Β· Limited seats

Apr 27 sold out Β· Apr 28, 30 + May 2 still open

Apr 27 just sold out.
3 sessions left β€” grab one fast.

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4 hours Β· 9 AM or 5 PM CET

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Apr 27 just sold out. 3 sessions left and filling up fast β€” lock yours in before it's gone.
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What is it?

A full-day, hands-on workshop to transform you from code contributor to well-rounded engineering leader.

  • Master algorithms beyond memorization
  • Approach system design with confidence
  • Think and communicate like a senior engineer
  • Apply security, accessibility, and observability in real products
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The curriculum

Five tracks. Eighteen+ concrete topics. Every one comes from real production code.

System Design

Architect systems that scale from day one

  • Scaling your project to use a feature-based architecture
  • Atomic Design
  • Implementing Server Driven UI
  • Microfrontend Architecture
  • Event Driven Architecture
  • Implementing a Backend for Frontend System
  • Learn how to tackle system design in the interview process

Design Patterns

Shared vocabulary. Reliable code. Fewer fires.

  • Exploring the most used creational, structural, and behavioral patterns
  • Implementing reliable design practices β€” circuit breakers, timeouts, and graceful fallbacks
  • Caching strategies β€” HTTP, CDN, service worker, and stale-while-revalidate
  • Retry patterns with exponential backoff and jitter
  • Feature flags for safe rollouts and instant kill switches
  • Spotting and refactoring anti-patterns in real React codebases

Observability

Stop guessing. Start measuring.

  • Logs, traces, and metrics β€” what each one is actually for
  • Play a scavenger hunt in a real system to explore o11y
  • Instrumenting a frontend with OpenTelemetry end to end
  • Dashboards that surface incidents before your customers do
  • SLOs, SLIs, and alerts that don't page on noise
  • Walking through a real production incident together

Modern Testing Practices

Tests that catch bugs without slowing you down.

  • New ways of testing your code that actually stick
  • Visual regression, component, and end-to-end tests
  • Contract testing between frontend and backend
  • Designing a test pyramid your team will actually maintain
  • Mocking strategies that don't lie β€” when to mock vs. integrate
  • Testing AI-powered features and flaky async flows

Security in Frontend Applications

Ship secure UI. Dodge the AI traps.

  • How to keep yourself β€” and your credentials β€” secure
  • Protecting against XSS, CSRF, spoofing, and common exploits
  • CSP, CORS, and secure headers that actually work
  • Auth patterns β€” OAuth, sessions vs. tokens, and safe refresh flows
  • Prompt injection and supply-chain attacks on AI tooling
  • Dangers of AI β€” what to never paste into a prompt

Plus more β€” Accessibility, AI workflows, and Algorithms as time allows.

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You will level up

  • Tackle complex technical interviews confidently
  • Make informed architectural decisions
  • Implement secure and accessible applications
  • Set up professional monitoring solutions
  • Apply design patterns to real-world problems

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 β†’

4-hour intensive Β· Morning or evening CET

250€

⏰ Limited seats Β· April 27 Β· April 28, 30 Β· May 2 β€” Apr 27 sold out. Once a session fills, that's it.

Grab my spot β†’

You also get

Everything else included with your seat β€” 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 module β€” perfect reference material.

Discount on future workshops

A standing discount on anything I teach next.

πŸ“‹ NEED TO CONVINCE YOUR BOSS?

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Pick the curriculum topics you care about, fill in your details, and we generate a tailored email β€” ready to send to your manager.

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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 β€” 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 Β· 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 β€” we actually exploited XSS vulnerabilities live."

Workshop attendee Frontend Developer Β· Athens

"What sets this apart from online courses is that Dan doesn't just teach β€” 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 Β· London

Your Instructor

Neciu Dan

Dan Neciu

Staff Engineer Β· Tech Co-Founder Β· International Speaker

Dan has spent 12+ years shipping production systems at scale β€” 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 β€” led teams across CareerOS, Glovo, AdoreMe
  • Speaker at React Alicante, Techorama Belgium, Utah JS, Frontmania Netherlands
  • Host of SeΓ±ors @ Scale podcast β€” 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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