Agentic Systems Engineer (TypeScript, .NET, MCP) - Remote

Wlgroup; Warszawa; Remote; PLN 466,000 - 700,000; Full time

Job summary

Wlgroup is seeking a senior software architect to transform a 10+ year legacy codebase into an agent-operable architecture. You will own system design at the intersection of software architecture, AI-agent orchestration, and engineering governance, with a remote-first team and US-morning hours.

You will decompose monoliths, enforce SOLID, DI, and Hexagonal Architecture; define MCP servers; and guide TDD and characterization testing to preserve legacy behavior while refactoring.

Qualifications

• 4+ years in software architecture, platform engineering, or technical leadership.
• Proven experience modernizing large, undocumented legacy systems.
• Deep hands-on expertise with TypeScript, .NET, and Node.js.
• Strong background in API design, distributed systems, and modular architectures.
• Practical experience with agentic development, MCP, LLM tooling, or AI-assisted engineering.
• Bias toward clean code, deterministic systems, and production-grade AI.

Responsibilities

• Architect and design agent-operable system architecture with modular boundaries and SOLID, DI, and hexagonal patterns.
• Lead MCP servers and agent context layer, exposing legacy APIs as typed AI-tools.
• Own contract-first API design as the primary interface between human intent and autonomous execution.
• Gatekeep AI-generated PRs, enforce TDD and characterization testing to preserve legacy behavior.
• Balance cost, speed, and architectural integrity in agent reasoning loops across projects.

Skills

Software architecture

Technical leadership

Distributed systems

API design

AI tooling awareness

Tools

TypeScript

.NET

Node.js

Job description

Want to design the architecture that lets AI agents safely refactor, test and ship production code? Then let's talk.

Our client acquires enterprise software companies and turns them into AI-native, profitable, scalable businesses. They are a remote-first, AI-forward team spread across the globe, offering high ownership, flexibility and impact, work across multiple products and technologies, and growth pathways across engineering, product and leadership.

The job: transform a 10+ year legacy codebase into a high-velocity, agent-operable architecture, at the intersection of software architecture, AI-agent orchestration and engineering governance.

Contract Type: Contract, full-time

Location: Fully remote from Eastern Europe, working US morning hours (Scrum).

What you'll do

Agent-operable system architecture

• Decompose legacy monoliths into agent-readable, modular systems with strict boundaries and single responsibility
• Lead incremental modernization using the Strangler Pattern, wrapping legacy logic in modern, contract-driven interfaces
• Enforce SOLID principles, Dependency Injection, and Hexagonal Architecture to ensure deterministic AI execution and low regression risk

Agentic framework & MCP leadership

• Architect and maintain the agent context layer: standardized Skills, Rules, and Commands for AI-driven engineering workflows
• Build and operate Model Context Protocol (MCP) servers exposing legacy APIs, services, and databases as typed, secure, AI-consumable tools
• Own contract-first API design as the primary interface between human intent and autonomous agent execution

Engineering governance & AI quality control

• Act as architectural gatekeeper for AI-generated pull requests, ensuring scalability, security, and long-term maintainability
• Mandate test-driven development (TDD) and characterization testing to preserve legacy behavior during refactoring
• Monitor and optimize agentic reasoning loops to balance cost, speed, and architectural integrity

What we’re looking for

• 4+ years in software architecture, platform engineering, or technical leadership
• Proven experience modernizing large, undocumented legacy systems
• Deep hands-on expertise with TypeScript, .NET, and Node.js
• Strong background in API design, distributed systems, and modular architectures
• Practical experience with agentic development, MCP, LLM tooling, or AI-assisted engineering
• Bias toward clean code, deterministic systems, and production-grade AI

Nice to have

• Experience with remote-first or globally distributed teams
• Background in SaaS transformations, scale-ups, or PE-backed environments
• Comfort operating in high-ambiguity, high-ownership settings