Scaler · Design Engineer · AI Build

How I designed and shipped an n8n learning simulator in 2 weeks

Try the Judge

Background

About Scaler

Scaler is a technology education platform that helps working professionals build industry-relevant skills through structured programs, mentorship and career support.

What is n8n?

n8n is a workflow automation tool. You connect blocks called nodes on a canvas. Each node does one task. It can read an email, ask an AI model to classify it or send data to another app.

My role

I worked as a Design Engineer and owned the concept, product design and engineering. The full project took two weeks. I shipped the production build in one week.

Outcomes

4.55 / 5

Average rating across 578 rated attempts

90%

Of those 578 gave four or five stars

73.2%

Of learners who started an attempt finished it

The problem statement

Scaler teaches n8n in its AIML and DSML courses. Learners use it to build automations for real clients. Classes run online. After the theory, learners join a one-hour practice session. The instructor shares their screen and solves one n8n problem step by step.

Learners

Using n8n for the first time in a live class.

Instructors

Teaching and supporting a full cohort at once.

Where the class struggled

Learners watched the shared screen and repeated each action. This produced a finished workflow. It did not show whether they understood each step. I spoke with about ten learners and instructors. I also observed an evening class. I noted where both groups needed help.

Learner notes

Learner theme

Learners copied the instructor's steps, so Scaler could not tell whether they understood the problem.

Learner theme

n8n sat outside Scaler, so learners had to return to the class chat for help.

Learner theme

Learners could not continue until the instructor answered.

Instructor notes

Instructor theme

Instructors could not help every learner during one live session.

Instructor theme

A completed workflow did not show how well each learner understood the problem.

Instructor theme

Scaler could not track or grade work done in n8n.

These notes are themes I synthesized from those conversations and the class I observed. They are not verbatim quotes.

Instructors' key concern was that
they couldn't grade learners' understanding of n8n.

The team explored hosting n8n inside Scaler's assessment platform so learner work could be tracked and graded. The reported estimate made that option too expensive.

₹70,000Estimated per month

Hosting n8n

₹5,000Estimated per month

In-house n8n Judge

Hover or focus on either bar to see the cost context.

So, I was tasked with building n8n Judge in-house

Because the hosted option was expensive, stakeholders wanted to test an AI-led alternative. I was asked to design and build that experiment. It had to help learners understand and build a workflow, and show instructors how well each learner understood it.

How I started off with this build

  • I observed a live class

    I watched how the instructor taught and how learners followed. I noted when learners asked for help.

  • I used n8n as a beginner

    I completed a workflow and watched beginner tutorials. The blank canvas offered many choices but no clear starting point.

The class I attended: one shared screen, one problem and a chat full of questions.

Two constraints I needed to keep in mind

01

AI could not calculate the score

AI is not deterministic, so it can produce different answers for the same input. I needed a fixed rubric to score every workflow consistently.

02

New problems had to be easy to add

I needed an authoring pipeline that let the team add a problem, its workflow, sample cases and scoring rubric without rebuilding the platform.

My idea for handholding and grading was to mimic my own design process

Designers break down a problem first, then design the solution, then design for the edge cases. I gave the Judge the same mental model so it could guide a learner and measure understanding in the same pass.

1

Understand

Break down the problem and identify the workflow.

2

Build

Add and configure one node at a time.

3

Stress test

Design for cases outside the normal path.

4

Result

Review the score, mistakes and next steps.

Fun fact: no Figma was used in my design process :D

For this project, I went with:

Next.js

Built the learner and instructor experiences.

Railway

Hosted the production application.

ElevenLabs

Generated the trained instructor voice.

AWS S3

Stored the generated voice clips.

Claude

Generated feedback and powered Ask Iris.

Cursor & Claude Skills

Ran the authoring pipeline for new problems.

Presenting to you, n8n Judge

Try the Judge for yourselfEst. time to solve: ~8 mins

Design decisions breakdown

1. Understand Phase: Breaking down the problem statement

Just like in the design process, I wanted learners to understand the problem before solving it. A learner can assemble a correct workflow without ever understanding its shape.

So the first phase is Understand: a short quiz about the workflow and its nodes that primes them before they reach the canvas.

Learners answer five questions about the workflow before the canvas opens. Each correct answer unlocks that node for the build.

Why this stage exists

  1. The instructor team wanted better outcomes from the n8n class: learners comfortable enough to build setups on their own. Understanding the problem is where that starts.
  2. Iris explains every answer, right or wrong, so the stage teaches while it grades.

2. Build Phase: Handholding learners at each step inside our n8n simulator

n8n Judge handholds learners through the build by simulating the n8n experience. When I tried n8n myself, the blank canvas gave me every option and no starting point, so the Judge walks learners through it one node at a time. Clicking the plus opens the same drawer n8n opens, and placing the right node moves them into its setup.

A real n8n workflow compared with the simulator.

3. Introduced voice to the Judge to bring it closer to an actual class experience

I gave Iris, our AI mascot and mentor, a trained voice based on the lead instructor,Shivank Agrawal. This made the guidance feel closer to the live class.

“Hey there! I’m Iris, your mentor. I’ll be guiding you through this whole n8n simulation. Ready when you are?”

Why voice, not just text

  1. In the live class an instructor talks learners through each step. Voice was the closest I could get to that inside a product.
  2. Iris still asks rather than tells out loud, so hearing the mascot does not shortcut the thinking.

4. Run Step: Helping learners visualise how an n8n node setup actually works

As part of learning how n8n works, I introduced Run mode. The node setup runs through several test cases for the given problem, which helps learners visualise how their setup actually behaves.

Each test case travels through the workflow the learner just built.

This stage is not graded

It exists purely for visualisation, so learners can see how n8n works. It also acts as a delight factor in the Judge.

5. Stress Testing: Challenging a learner's understanding of the node setup

An n8n node setup can pass its test cases and still fail at a few edge cases. So this phase asks two “what if” questions to test the learner's understanding of the entire setup.

The learner explains what should happen when the normal path breaks.

Why the attempt ends here

  1. These questions test whether a learner understood the problem and the setup, not whether they reproduced the class demo.
  2. These are graded as well, and appear as part of the final report.

6. Result: Showing learners how they performed and where to improve

I developed a rubric system that calculates a deterministic score, while Claude provides pointers for the learner to improve, based on the interactions recorded during the attempt.

The server calculates the score

The server scores each attempt against the rubric, which keeps the score deterministic.

Claude explains the result

Claude turns the result into clear strengths, gaps and next steps. It cannot change the score.

The report connects the score to the decisions made during the attempt.

7. I also instrumented the product, for analytics and to find out where it can be improved

The admin panel was built for the Judge. It captures the ratings and feedback learners leave, and it also holds interaction traces. Those traces tell me where learners are dropping off, and I can take those insights into user research calls.

8. Learners can take the workflow they built into real n8n

The simulator is a bridge into n8n, not a replacement for it. Once a learner clears the score threshold, the report offers the workflow as a real n8n JSON file. They import it into n8n, add their own credentials, and carry on building in the actual tool with the node setup they just made.

The workflow leaves the Judge as a file n8n can open, with the same nodes and connections the learner assembled.

Why this matters

  1. The class existed to get learners building in n8n. An exercise that ends inside a simulator teaches the model but leaves them at the same blank canvas afterwards.
  2. It gives the attempt something to show for it. The learner walks away with a working file, not only a score.

Iterations and variations

The first build was a bare canvas with a node palette. It worked, and it taught nothing.

Every version after that went to the instructor team. Their feedback added the handholding, pushed the editor closer to real n8n, and shaped the rubric behind the score. Two days of stress testing closed it out.

Outcomes and metrics

809

Attempts completed across six problems

340

Learners behind those attempts

578

Of those attempts left a star rating

367

Of those attempts left a written comment

Straight from the rating box

nice experience with iris dropping in for each input and correcting the mistakes
Scored 85/100
This is some serious AI mentor. I felt really engaging and building felt like playing a game. KUDOS
AmarthiyanScored 93/100
comprehensive guidance on the case study and voice over introduction to the problem helped in understanding the problem clearly.
Kaushal DhruvScored 76/100
Interactive, New way to improve learning experience and Gain valuable insights
Mohinder PalScored 90/100
It was the thing missing in the course and we need it badly
Navi JhaScored 70/100
really engaging, builds confidence, but too much hints given, which makes it very easy to solve
Jagadeep NScored 92/100
The walkthrough was smooth. Easy to understand and implement.
Ash KumarScored 91/100
Very interactive and close to real life scenarios
Manoj SripathiScored 100/100

What I changed after talking to learners

After release I called learners who had already used the Judge. I pulled each one from the admin panel first, so I could see where their attempt stopped before I asked them anything.

The calls gave me four problems to fix. What the learner said is on the left. What I did about it is on the right.

  • What a learner said

    Iris said “If you are stuck, let me know. I can help you.” So I clicked the “Ask Iris” button. But it did not reply.

    What I changed

    Fixed Ask Iris

    The API key was broken, so Iris could not answer. I fixed the key. I also changed the model provider from Anthropic to OpenRouter. OpenRouter switches to another model on its own when one model is down.

  • What a learner said

    Iris is communicating to me in voice, but when I responded, it did not respond back.

    What I changed

    Rewrote Iris's voice copy

    Iris used to say “If you have any questions, please tell me.” A learner heard that and spoke back to her. So I changed the line to “If you have any questions, ask them through the Ask Iris button.” It is a small change, and it removed the confusion.

  • What a learner said

    There is no retry button at the end. Can you please fix this?

    What I changed

    Added retry and next

    I added a retry button to the result page. I also added a next button, so a learner can move straight to the next problem.

  • What a learner said

    Once I started the problem there was no way back. I could not get to the other problems. Please fix this.

    What I changed

    Made the logo a way out

    A learner can now click the Scaler logo on any screen to go back to the home page.

Reflections and key takeaways

  • I wore three hats on this one: designer, engineer and product owner. Holding all three meant a decision could be taken, built and tried the same day.
  • Instrumentation is what made the research possible. The traces told me which learners to call after release, and what to ask once I had them on the phone.
  • I started from the problem rather than the tool, from what a learner has to understand before they can build. The four stages came out of that, and the rubric followed.

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