Back end Engineer

Arena

Backend Engineer role at Arena focusing on scalability and AI features development. Collaborate with product and engineering teams to enhance app performance for high-traffic applications.

Posted 5/22/2026full-timeRemote • 🇧🇷 BrazilMid-LevelSeniorWebsite

Tech Stack

Tools & technologies

AWSJavaScriptMongoDBNode.jsTypeScript

About the role

Key responsibilities & impact

Collaborate with product and engineering teams to ship AI-powered features
Make the app and API service faster, more scalable, and flexible
Design and build AI Agents, RAG pipelines, model fine-tuning, and crawling.
Ensure high performance and availability of applications

Requirements

What you’ll need

3+ years as a backend developer
Experience with high-traffic and high-performance applications
Curious developer who experiments with AI and AI agents every day.
TypeScript;
Node.js;
TDD, BDD, or ATDD;
REST APIs;
MongoDB, AWS DocumentDB, or other document database;

Benefits

Comp & perks

4 weeks of paid time-off
Learning and Development budget
Competitive salary package & benefits
Ability to put your stamp on real-world AI applications

ATS Keywords

✓ Tailor your resume

Applicant Tracking System Keywords

Tip: use these terms in your resume and cover letter to boost ATS matches.

Hard Skills & Tools

TypeScriptNode.jsTDDBDDATDDREST APIsMongoDBAWS DocumentDBAI Agentsmodel fine-tuning

Soft Skills

collaborationcuriosityexperimentation