NumberLink: Identity with Phone-First Profiles
Replacing friction-heavy email signups with a seamless phone-number based identity system. We built a chat-driven onboarding flow that reduced drop-offs by 40%.
Role
Lead Engineer
Timeline
6 Months
Client
NumberLink
Stack
React, Node.js, MySQL
98/100
Lighthouse Score
The Challenge
Traditional email-password flows were causing a 65% drop-off rate during onboarding. Users found the verification link process cumbersome, especially on mobile devices where switching apps kills momentum.
We needed a system that felt conversational, instant, and secure, leveraging the device users already had in their hands: their phone.
App Switching
Email verification required switching apps, killing user momentum.
Password Fatigue
Complex password requirements caused user frustration and abandonment.
Legacy Forms
Non-responsive forms created poor mobile experiences.
Friction Points Identified
We analyzed user behavior and identified three critical friction points that were causing the high drop-off rate.
Key Issues
- close App switching for email verification
- close Password complexity requirements fatigue
- close Non-responsive legacy forms
Chat-Driven Solution
We redesigned the onboarding as a conversational UI. Instead of a form, users "chat" with the system to set up their profile.
Natural Language Input
Inputs are parsed in real-time. Typing "I'm Alan, a designer" auto-fills the Name and Role fields instantly.
Optimistic UI
State updates locally before server confirmation, making the chat feel instantaneous (0ms latency perception).
Dynamic Component Rendering
The chat interface isn't just text. The server can push interactive widgets (calendars, maps, uploaders) directly into the stream based on context.
Platform Architecture & Data Flow
High-level overview of the request lifecycle and how data flows through the system.
Request lifecycle overview
Isomorphic Rendering: Initial load is SSR for SEO, subsequent navigation hydrates to CSR for speed.
Race Condition Handling: Redis locks prevent duplicate phone number verification requests.
Performance & SEO Strategy
Since user profiles are public-facing, SEO was critical. We implemented a hybrid rendering strategy.
- check_circle Server-Side Rendering (SSR) for SEO
- check_circle Image Optimization with WebP format
- check_circle First Contentful Paint under 1.2s
Project Outcomes
Reduced onboarding drop-off significantly compared to the old email flow.
Largest Contentful Paint improved by 2.5 seconds on 3G networks.
Robust error handling and Redis caching ensured high availability.