Senior AI Software Engineer - Remote & Legacy Modernization

Nextlane; Madrid; Hybrid; EUR 65,000 - 100,000; Full time

Benefits offered by this job

Remote work up to 3 days/week

Work-life balance

Summer schedule on Fridays

Referral bonus €1500

Flexible remuneration

Private medical insurance

Continuous learning

Vacation 23 days

Teambuilding

Job summary

Nextlane is seeking a Mid/Senior Software Engineer to champion AI in development. You’ll work on modern C#/.NET stacks and legacy COBOL/Delphi/PowerBuilder code, using AI agents to accelerate delivery and modernize critical systems.

If you enjoy blending legacy and modern tech and driving innovation across a global team, this role is for you. The position emphasizes AI advocacy, development excellence, and collaboration with product, QA, DevOps, and peers.

Qualifications

• 4 to 6 years of professional software development experience.
• Proven hands-on experience with AI coding agents (GitHub Copilot, Cursor, Claude Code).
• Experience building agentic workflows or custom AI tooling.
• Willingness to work with legacy technologies (COBOL, Delphi, PowerBuilder, FoxPro, WinDev).
• Solid experience with C#/.NET and/or React/TypeScript/JavaScript.
• Experience with SQL databases and testing tools (Playwright, Cypress, Newman).
• Fluent in English; French/Spanish is a plus.

Responsibilities

• Lead by example in daily use of AI coding agents across development, testing, documentation and code review.
• Configure and maintain AI agent setups and reusable workflows for the team.
• Share knowledge through demos, pair programming and internal workshops.
• Identify repetitive tasks suitable for agentic automation and propose improvements.
• Develop and maintain features across backend and frontend and modernize legacy codebases.
• Collaborate with product, QA, DevOps and other engineering teams and mentor less experienced engineers.

Skills

AI coding agents

C# / .NET

React / TypeScript / JavaScript

Git

CI/CD

Agile practices

English fluent

SQL / Relational databases

Tools

Git

CI/CD

Azure / AWS / GCP

Job description

Nextlane is seeking a Mid/Senior Software Engineer to champion AI in development. You’ll work on modern C#/.NET stacks and legacy COBOL/Delphi/PowerBuilder code, using AI agents to accelerate delivery and modernize critical systems.

If you enjoy blending legacy and modern tech and driving innovation across a global team, this role is for you. The position emphasizes AI advocacy, development excellence, and collaboration with product, QA, DevOps, and peers.