Senior Full-Stack Engineer — Hybrid + Equity

Lexroom Srl; Barcelona; Remote; EUR 83,000 - 138,000; Part time

Job summary

Lexroom Srl is seeking a Sr. Full-Stack Software Engineer to support an AI training project focused on software development, debugging, code evaluation, and cross-language translation. This is a remote contractor position with ~15 hours per week.

You will contribute to both front-end and back-end systems, review AI-generated code for quality and security, and collaborate with a distributed team across languages and platforms.

Qualifications

• Extensive experience in full-stack development across frontend and backend technologies.
• Strong proficiency with Python, JavaScript/TypeScript, and modern frameworks.
• Experience building and consuming APIs and data models.
• Ability to understand and adapt to unfamiliar codebases and architectures.

Responsibilities

• Develop and debug front-end and back-end applications.
• Build features, APIs, services, and data models.
• Understand and work across unfamiliar codebases.
• Troubleshoot application, API, database, and integration issues.
• Review and evaluate AI-generated code for correctness, security, performance, and maintainability.
• Translate and adapt software builds between programming languages.

Skills

Python

React

JavaScript

Java

Node.js

Rust

Go

TypeScript

Full-stack development

APIs & databases

Tools

APIs

Databases

Job description

Sr. Full‑Stack Software Engineer - Remote

Full-Stack Software Engineer

Location: Global, Fully Remote
Job Type: Contractor | ~15 hours/week
Schedule: Flexible

We're looking for experienced Full-Stack Software Engineers to support an AI training project focused on software development, debugging, code evaluation, and technical problem-solving.

Key Responsibilities

• Develop and debug front-end and back-end applications.
• Build features, APIs, services, and data models.
• Understand and work across unfamiliar codebases.
• Troubleshoot application, API, database, and integration issues.
• Review and evaluate AI-generated code for correctness, security, performance, and maintainability.
• Translate and adapt software builds between programming languages.

Required Skills

• Python
• React
• JavaScript
• Java
• Node.js
• Rust
• Go
• TypeScript
• Strong full-stack development experience
• Experience with APIs, databases, application architecture, and debugging

Hiring Process

1. Submit application and screening questions.
2. Complete a ~30-minute AI interview.
3. Complete a technical assessment, if required.
4. Hiring manager review.