Senior Agentic Systems Architect (TypeScript, .NET, MCP) - Remote

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

Job summary

Wlgroup seeks a senior software architect to transform a 10+ year legacy codebase into a fast, agent-operable architecture. You will decompose monoliths, apply the Strangler pattern, and enforce SOLID, DI and hexagonal architecture to ensure deterministic AI execution.

In a remote-first, global team, you’ll design the agent context layer, build MCP servers that expose legacy services as typed tools, and own contract-first API design between human intent and autonomous agents.

Qualifications

• 7+ 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

• Architectural governance for AI-generated PRs ensuring scalability, security and maintainability
• Decompose legacy monoliths into agent-readable modular systems with clear boundaries
• Lead modernization using the Strangler pattern wrapping legacy logic in contract-driven interfaces
• Enforce SOLID principles, Dependency Injection, and Hexagonal Architecture for deterministic AI execution
• Design and maintain the agent context layer: Skills, Rules, Commands for AI-driven workflows
• Build and operate MCP servers exposing legacy APIs as typed, secure tools
• Own contract-first API design as the main interface between human intent and autonomous agents
• Monitor and optimize agentic reasoning loops balancing cost, speed and architecture
• Promote test-driven development and maintenance of legacy behavior during refactoring

Skills

TypeScript

.NET

Node.js

API design

Distributed systems

Modular architecture

Agentic development

MCP

LLM tooling

AI-assisted engineering

Tools

Strangler pattern

Hexagonal Architecture

DI

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

• 7+ 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