Lemon.io: Senior Full-stack Developer

[Hiring] Head of Insights @Leonardo.Ai

November 27, 2025

[Hiring] Product Owner @IBS Career Portal

November 27, 2025

Published by Coupea on November 27, 2025

Tags

Need a pro? Hire top freelancers — fast.

Design, marketing, development & more — starting at affordable prices.

Explore Fiverr →

Headquarters: New York, NY

URL: https://lemon.io

Are you a talented Senior Developer looking for a remote job that lets you show your skills and get decent compensation? Look no further than Lemon.io — the marketplace that connects you with hand-picked startups in the US and Europe.

Currently, we are seeking a Senior Full-Stack Developer for our client. It’s a great opportunity, as they are one of the fastest-growing YC companies. Their investors include Y Combinator and Box Group, and they support leading AI labs. Joining this project offers the chance to play a key role in the AI movement.

Details:

40h / week – very likely a 6-day work week due to the fast-paced nature of the project
start date: within 2-3 weeks
Full-time
within 2-3 weeks
2-3 months with potential to extend to 1-year engagement.
(GMT -8:00) Pacific Time (US & Canada)

What the Company Does

Develops tools and services for creating high-precision datasets used to train advanced AI models.
Builds simulated environments and functional prototypes of well-known digital products (such as communication platforms, CRM systems, productivity tools, financial interfaces) so AI agents can learn to complete real-world tasks.
Creates internal platforms for data management, quality control, and automation of data generation workflows.
Works on long-term technologies that help AI systems better understand complex tasks, business logic, and user interfaces.

Requirements:

5+ years of experience with React.js and Node.js
Expertise in JavaScript, Tailwind CSS, Next.js, AWS, and SQL is a must

TASKS/RESPONSIBILITIES

Develop full-stack web applications from the scratch, replicating existing enterprise software.
Collaborate with internal management and technical leads.
Participate in a take-home assessment and interviews as part of the selection process.
Deliver production-ready, scalable solutions using Next.js, Tailwind, SQL/Redis, and related technologies.

IDEAL PROFILE

You have a diverse skillset and are open to learning new technologies.
You have strong experience building stuff from scratch.
Your background includes products that are used and loved by many; working at big companies or popular startups is a big bonus.

IMPORTANT

You are open to weekend work. It’s likely going to be a 6-day work week regularly.
You are open to completing a test task for this project, which will take roughly 10 hours and will be compensated (500$).

Other Options from Lemon.io

NOT YOUR TECH STACK?

We have different projects for Senior Developers, so if you have 4+ years of commercial experience in software development and you are fluent with React & Node.js, React & Python, Python&Node, Swift & SwiftUI, Golang, AI Engineering, Data Engineering, Python & LLM, Blockchain, WordPress, Unreal Engine, Vue & PHP, MLOps, React & PHP, Rust, Angular & PHP, Game Development, Svelte & TypeScript, Svelte & Node, Svelte & Python, or Shopify & JavaScript we would be happy to communicate and provide you with a project that matches your experience. Just apply, and we will share more details with you.

If your experience matches our requirements, be ready for the next steps:

VideoAsk — watch a short video about our startup, up to 10 minutes
Complete your profile on our website
30-minute screening call
Technical interview
Feedback
Magic Box (we are looking for the best project for you).

P.S. We work with developers from 50+ countries in different regions: Europe, LATAM, Asia (Philippines, Indonesia), Oceania (Australia, New Zealand, Papua New Guinea), Canada, and the UK. However, we have some exceptions.

At the moment, we don’t have a legal basis to accept applicants from the following countries: