Nexstem.ai - Frontend Developer
Interview Process
Assignment Round
I was asked to build a DAG (Directed Acyclic Graph) Editor from scratch with features like:
- Node dragging and connection
- Auto layout using Dagre
- Add/remove nodes dynamically
- Live re-rendering
🔗 Live Project: dag-editor-seven.vercel.app
💻 Codebase: GitHub Repo
📢 Post: Assignment Task LinkedIn Post
🛠 Stack Used:
- React.js
- ReactFlow
- Dagre layout engine
- Tailwind CSS
Technical Round
The interview focused on:
-
Assignment Deep Dive
- Architecture of the DAG Editor
- Why ReactFlow and how it works internally
- Optimizing performance and state handling
- How Dagre was integrated with node layouts
-
JavaScript Fundamentals
varvsletvsconst: differences, scope, and hoisting- What is hoisting and closure with examples
- Output-based questions on:
- Asynchronous execution
- Event loop and call stack
- Closures and lexical environment
-
React Coding Questions
- Controlled vs uncontrolled components
- Use of
useEffectand dependency array - Writing simple live coding components
Detailed Experience & Tips
The interview process at Nexstem.ai was both practical and concept-driven. The assignment round tested not just coding skills but also architectural thinking and UI/UX understanding. I focused on delivering clean code, modular components, and intuitive user interactions. In the technical round, what stood out was the focus on "why" I made certain decisions - like choosing ReactFlow for managing complex node structures, and how I used Dagre for layout computation.
The JavaScript questions were deep and concept-heavy, touching on real-world implications of closures, hoisting, and scope behavior - topics many skip during surface-level prep. For React, they weren’t just interested in knowing the API, but how I used hooks, managed side-effects, and kept components performant and maintainable.
My tips for others:
- Don’t just copy projects, build something original that solves a problem or shows creativity.
- Be prepared to explain every decision in your code (tech stack, structure, logic).
- Practice JavaScript with a focus on core concepts, not just DOM or frameworks.
- Explore open-source tools like ReactFlow to stand out in frontend interviews.
- Make sure your resume is project-first, and clearly highlights your contributions.
Overall, it was a great learning experience, and the kind of interview that actually evaluates you as a builder, not just a coder.