April 2026   -   Duration 20 Days

The Haxoniq Challenge: The Million-Seat Flash Sale

Deadline

Join the challenge,  the clock is ticking!

Join now for

A chance to win a $ voucher Prize

Check the evaluation criteria below to know how

700$

Frist Place

200$

Second Place

100$

Third Place
What to expect during the challenge

The Scenario

You are the Lead Architect for the "Global Finals 2026." We are releasing 1,000,000 tickets to the public at 12:00 PM sharp.
The marketing team has done their job too well. We expect 100,000 concurrent users to hit the "Buy" button the millisecond the sale opens.

   The Mission

Build a High-Performance Booking Application that will handle this traffic.
Your system must ingest a chaotic stream of purchase requests, assign seats, process payments, and update the stadium map in real-time,

without selling the same seat twice.

   The Challenge

We aren't looking for a pretty e-commerce website. We are looking for a Ferrari-grade backend engine.

1. The Scale
  • Inventory: 1,000,000 specific seats (Section, Row, Seat Number).
  • Load: You must process a simulated stream of 10,000 requests per second.
  • Goal: Sell out the entire stadium in under 10 minutes while maintaining 100% data consistency.

2. The Hard Constraints (The "Why It Breaks")
  • The "Highlander" Rule: Every seat must have exactly one owner. Zero double bookings allowed.
  • The "Squad" Rule: Users buy up to 4 tickets at once. They must be adjacent (e.g., A1, A2, A3, A4). If A3 is taken, the whole group fails. You cannot split groups.
  • The "Wallet" Atomicity: Each user has a prepaid wallet. You must atomically reserve the seats AND deduct the funds. If one fails, both roll back.

   The Deliverables

You must submit a single application repository containing two parts:
A. The Core Engine (Backend)
  • This is where you win or lose.
  • Input: An HTTP/WebSocket endpoint that accepts a high-velocity stream of BookTicketCommands.
  • Logic: The "Black Box" that enforces the rules above.
  • Output: A stream of confirmed TicketSoldEvents.
  • Tech Stack: Java/Kotlin is preferred. Use of Axon Framework and Axon Server is highly recommended to handle the distributed state and event sourcing.
B. The Operational Dashboard (Frontend)
  • Philosophy: Function over Form. We don't care about CSS, logos, or animations.
  • Requirement: A single-page "Heatmap" of the stadium.
    - Gray: Available
    - Red: Sold (Updates live via WebSocket/SSE)
    - Yellow: Reserved/Pending
  • Why? To prove your app is actually working in real-time during the stress test.

Evaluation Criteria

Your submission will be subjected to the "Bot Swarm" an automated stress test script.

  •    Consistency  40%

  • Pass/Fail. If we find one double booking or one negative wallet balance, you are disqualified.

  •    Throughput   30%

  • Events Per Second. How fast can you sell out the stadium? (< 10 mins = Gold Tier)

  •    Architecture  20%

  • Did you use a global lock (Bad)? Or did you implement Dynamic Consistency Boundaries to group seats on the fly (Excellent)?

  •    Visuals          10%

  • Does the dashboard update in real-time without crashing the browser?
    Did you find the imposter user?
Using the Axoniq tech stack would be preferred, but it is not a requirement and wouldn't be a success metric.

You will benefit the most if you are a Senior/Junior Developer

New to Event-Driven architecture and Event-sourcing.

Already using Axon Framework and/or Axon Server.

Meet our Judges

Panel of expert developers 

During the hackathon, our developers and solution architects, and builders of the Axoniq Platform will be grading and providing feedback for your challenge submissions.
Marc Klefter
Product Archtict
Allard Buijze
CTO
Steven
Van Beleen
Framework Lead
Stefan Dragigc
Axon Server Lead Developer
Mitchell Herrijgers
Axoniq platform Lead
The Haxoniq Challenge: The Million-Seat Flash Sale