Senior Fullstack Engineer @WhatsappX (eFounders)
Hexa (eFounders)
Hexa (eFounders)

Senior Fullstack Engineer @WhatsappX (eFounders)

  • Paris…
  • Permanent contract 
    Hybrid remote
    Education: Not specified
    Experience: Not specified

    This position was filled!

    Who are they?

    🚀 eFounders is a startup studio, part of Hexa

    We partner with talented cofounders to build the future of product-led SaaS.

    We pioneered the startup studio model in 2011 and have since launched over 30 companies (7 of them have made exits) with $700M in funding and now reaching a valuation of over $5 billion - including Front, Aircall and Spendesk which recently became unicorns.

    Today, over 2,500 employees across the world work in a startup which started out as a simple mockup right here at eFounders.

    Who we are. We are passionate builders with one common goal: to build the next generation of SaaS companies. We’re a team of hands-on expert in Product, Design, GTM and more, ready to help founders get their startups off the ground.

    Our companies:  Roundtable • ElbaDotfileSwanCycleFolkUpflowYousign + many other startups and more to come 🚀

    💬 We are WhatsAppX

    We are WhatsAppX (generic name) and our ambition is to supercharge online sales through conversation.

    Businesses are starting to leverage the power of social media chats (WhatsApp, Messenger, Telegram) to engage with consumers, and WhatsApp has been repositioning itself as a place for business conversations. We believe that companies will gain from using WhatsApp to sell products and services, like emails, SMS and phone calls today.

    Our product will turn WhatsApp into a powerful sales channel by bringing together in-chat payment, checkout, product catalog, and appointment booking features in a collaborative tool.

    We’re at the beginning of our journey and are already backed by eFounders, making now a great time for you to join us!

    WhatsAppX has been founded by an ambitious team:

    Job description

    We are seeking a founding engineer to help us build the foundations of our tech stack and team. This person should be excited about joining an entrepreneurial journey and significantly impacting the product and technical stack. We’re looking for someone who’s independent and eager to navigate uncharted waters.

    This is a unique opportunity to join WhatsAppX as one of the first engineers and significantly impact the product and technical stack.

    Previous experience in a startup or scale-up organisation is highly valued.

    🎯 Your mission

    You will work closely with Thomas (CTO) and Paul (CEO) to build a world-class product from scratch.


    • Build the foundations of the platform

    • Build, maintain and test product features end-to-end, from the user interface to the API, from the documentation to the security aspects

    • Work closely with the founders and product team of eFounders to shape the platform

    • Implementing coding best practices (clean code, test, typing…), help us build a very high-quality codebase and set the foundations of what it will become

    Preferred experience

    • 4+ years of experience in a full-stack web dev position, or a backend dev position (ready to jump-in on frontend tasks)

    • Strong experience in Node.js (vanilla or one of its backend variants: Express, NestJs, …). Cherry on the cake: experience in NestJs

    • Experience with relational database

    • Ownership mentality: you like to take initiative and build features from conception to production

    • Product & business sense: you care about what you build and the value you create for users. “code is just a way to a bigger mean” → this sentence resonates with you

    • Team player: you enjoy learning from each other, thrive in teams and communicate with ease

    • Bias for action: you are a doer and like to build, no task is below you

    • Strong attention to detail: code quality and good UX is important to you and you set a high bar

    💻 Our tech stack

    This is the stack that we work with, you don’t have to know it all:

    • Tools: Github, Github actions, Postman, Copilote etc…

    • Frontend: React, TailwindCss, TailwindUI

    • Backend: NestJs monolith for the API, outposts with serverless Lambdas

    • DB: Postgres & TypeORM (ORM)

    • Testing: Cypress, Jest

    • Infra: AWS, Serverless Lambda, CDK

    Engineering mindset

    • We want to go fast. Velocity is our greatest weapon

    • We strive for software craftsmanship and good practices, such as clean code, peer programming, and code reviews

    • Develop, deploy and maintain features. We own our choices and our code!

    • The tech serves the company’s goal, not the other way around

    • Each piece of code serves a specific purpose and delivers value

    • We are here to ship, build a startup and to have fun while doing 🚀


    • Competitive compensation and equity package

    • Latest Macbook Pro + Monitor

    • Awesome colleagues with high ambitions (the founders + Hexa (eFounders) core team)

    • Lovely offices located in the heart of Paris or Brussels (Hybrid working model). A few days a week in the office (Brussels or Paris), the rest is up to you.

    • Quality-driven environment

    • A strong product and technical culture

    Hexa is committed to creating a diverse environment. All qualified applicants will receive consideration for employment irrespective of gender, origin, identity, background and sexual orientation.

    We know there’s a long way to go regarding diversity in our industry, which is why we encourage all applicants- especially those listed above- to apply to our open positions.

    Hexa (eFounders)
    Hexa (eFounders)

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