Founding Full-Stack Product Engineer — Fintech / Payments

Company Description

Handl is revolutionising the infrastructure for internet-native businesses by providing a unified platform for creators and digital founders to launch, monetise, and scale their ventures. By combining payments, tax compliance, merchant-of-record structures, affiliate distribution, and revenue sharing, Handl offers a scalable solution tailored to modern digital companies. Operating globally and powering live transactions, Handl is designed to simplify complexity, enhance margins, and unlock new opportunities in the digital economy. Just as Shopify transformed e-commerce and Stripe redefined online payments, Handl is poised to become the foundational operating system for digital brands. At Handl, we aren't just improving the stack — we're rebuilding it.

Role Description

This is a full-time role for a Founding Full-Stack Product Engineer. As a core team member, you will design and develop scalable systems to support the growth of internet-native businesses.

We already have an initial prototype built, but we are now ready to build the real production version of the platform.

Handl will integrate several third-party infrastructure providers, including:

  • Payment orchestration
  • Tax calculation/compliance
  • CRM/order management
  • Payment/payout rails
  • KYC/KYB and identity verification

We need someone who can create the user facing product: the user interface, onboarding flows, dashboards, settings, merchant account setup, API/OAuth connection flows and data views.

This role is ideal for a strong full-stack product engineer who can take a prototype and turn it into a clean, scalable SaaS application.

What You'll Be Building

You will help build the first live version 1.0, including:

  • Merchant onboarding flow
  • User registration and login
  • Company/account setup
  • KYC/KYB flow
  • OAuth/API connection flows
  • Merchant dashboard
  • Transaction/order views
  • Revenue and payout dashboards
  • Tax/compliance status views
  • CRM/order data views
  • Payment orchestration data
  • Payout/payment rail data
  • Tax calculation/status data
  • Admin dashboard
  • User roles and permissions
  • Settings pages
  • API connection management
  • Webhook handling
  • Basic internal backend/database structure
  • Clean UI based on our existing prototype

Important Clarification

We are not looking for someone to design a few Figma screens only.

We need someone who can actually build the platform.

You should be comfortable working across:

  • Frontend
  • Backend
  • APIs
  • Authentication
  • Databases
  • Third-party integrations
  • SaaS dashboards
  • Clean UI/UX

You do not need to be a specialist in payments infrastructure, but experience with fintech, payment platforms, SaaS dashboards, marketplaces, CRMs, affiliate platforms, or financial admin tools would be a big advantage.

Required Skills

  • Strong experience building SaaS platforms or web apps
  • Strong frontend skills
  • Good UI/UX judgment
  • Experience building dashboards and admin panels
  • Experience integrating third-party APIs
  • Experience with authentication and user roles
  • Experience working with webhooks
  • Experience with OAuth or API key-based integrations
  • Ability to turn a prototype into a real product
  • Ability to work quickly and independently
  • Good communication skills
  • Ability to suggest better product flows, not just follow instructions blindly

Preferred Tech Stack

We are open to recommendations, but we are considering:

  • React / Next.js
  • Tailwind CSS
  • Node.js / Express / NestJS
  • PostgreSQL / Supabase
  • Prisma
  • Vercel / Railway / Render / AWS
  • REST APIs
  • Webhook-based architecture

Please mention your preferred stack when applying.

Nice-to-have Experience

  • Fintech dashboards
  • Payment orchestration platforms
  • Merchant onboarding
  • KYC/KYB flows
  • Tax/compliance integrations
  • CRM integrations
  • Affiliate tracking platforms
  • Payment/payout systems
  • Marketplace platforms
  • SaaS admin panels
  • Replit prototypes
  • No-code/low-code MVPs being converted into production apps

What We Already Have

  • Existing prototype
  • Clear product vision
  • Core platform providers selected
  • Defined user flows
  • Defined commercial model
  • Defined MVP direction
  • Internal team ready to move quickly

We need someone who can take this and turn it into a clean, usable, production-ready MVP.

First Phase Of Work

The first phase will likely include:

  • Reviewing the existing prototype
  • Recommending the best production tech stack
  • Creating a proper frontend structure
  • Building the main dashboard layout
  • Building merchant onboarding
  • Building login/account setup
  • Creating API connection screens
  • Setting up database structure
  • Connecting initial third-party API endpoints
  • Creating admin/internal views
  • Preparing the app for future scale

What We Are Looking For In Your Application

Please include:

  • Examples of SaaS dashboards or web apps you have built
  • Examples of API integrations you have worked on
  • Your recommended tech stack for this project
  • Whether you are stronger in frontend, backend, or full-stack
  • Your availability
  • Your estimated approach for turning a prototype into a production MVP
  • Any relevant fintech, payment, marketplace, CRM, or compliance experience

Generic copy-and-paste applications will be ignored.

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Job Details

Company
Handl
Location
London, England, United Kingdom
Posted