AI Agents & Platforms
Building AI-powered products with LLM integration, MCP servers, and multi-agent orchestration.
Developer Tooling
E2E testing infrastructure, debugging tools, AST compilers, and internal platforms.
Full-Stack Architecture
Scalable systems with React/Next.js + NestJS, cloud-native on AWS & GCP.
My Experience
My professional journey and the roles I've taken on throughout my career.
Software Engineer
Designed and implemented AI-powered E2E test recovery and debugging tools, reducing test flakiness and manual investigation time by automating root-cause analysis and fix suggestions. Built MCP servers enabling AI agents to step through test code, evaluate execution, and interact with browser instances for comprehensive test analysis. Developed benchmarking platforms with AI judges to assess solution correctness at scale.
Founding Engineer
Architected and developed a production AI agents orchestration platform enabling multi-agent collaboration through specialized team configurations. Implemented real-time monitoring of agent reasoning steps, tool usage, and decision-making processes. Built advanced chat interfaces displaying transparent agent behavior and supporting multiple LLM models with various thinking modes. Integrated MCP protocol for extensible agent capabilities.
Senior Software Engineer
Led full-stack development across multiple high-impact projects including blockchain-based green energy traceability, eCommerce platforms, and visual testing infrastructure. Architected scalable solutions using NestJS, Next.js, and cloud platforms (AWS, GCP). Drove technical decisions on architecture patterns (DDD, Event Sourcing), delivered production systems with complex third-party integrations (CRM, invoicing, contracting), and mentored team members on best practices. Took full ownership of projects from requirements gathering through deployment.
Software Engineer
Core contributor to AdminJS, an open-source auto-generated admin panel for Node.js applications used in production systems. Implemented framework adapters (Express, NestJS, Hapi) and ORM connectors (Sequelize, TypeORM, Mongoose, MikroORM). Maintained production-ready library, addressed user issues, and shipped new features. Collaborated with cross-functional teams to deliver scalable web applications using React and Node.js.
Junior Java Engineer
Built foundational backend engineering skills while maintaining large-scale Java codebases. Implemented automated tooling that streamlined CI/CD processes, reducing build times and improving deployment reliability for the team.
Featured Projects
A selection of projects showcasing my work across AI, developer tooling, and full-stack systems.
AI-Powered Self-Healing Test System
- ‣LLM-based self-healing that auto-recovers broken E2E tests from UI changes
- ‣Full agent workflow: session management, PR creation, follow-up messaging
- ‣Benchmark platform with AI judge for correctness assessment
Multi-Agent AI Orchestration Platform
- ‣Sole developer: monorepo init to production deployment
- ‣Real-time monitoring of agent reasoning, tools, and responses
- ‣Multi-tenant RBAC, background scheduling, and analytics dashboards
Interactive Code Evaluation Platform
- ‣Line-by-line stepping, step-into, loop control via AST transformation
- ‣Source map support and runtime code injection
- ‣Full web-based debugger UI with expression evaluation
More Projects
MCP Server for E2E Test Debugging
Built an MCP (Model Context Protocol) server for Playwright with CDP-based network request tracking, multi-tab support, and pause-on-error debugging via source code instrumentation. Enables AI agents to step through test code, evaluate expressions, and interact with web pages for comprehensive test analysis. Published across 14 releases.
AI Chat Widget for Test Generation
Developed an AI chat widget for running and generating Playwright-based tests. Features context-aware test generation from HTML and page screenshots, an element inspector for click-based selection, test code auto-fixing, multiple LLM model support, and configurable thinking modes.
Shadow CEO Decision-Support Agent
Developed Cesar, a Shadow CEO AI agent for executive decision support. Leverages analytical frameworks including AHP (Analytic Hierarchy Process), Kepner-Tregoe methodology, decision trees, and scenario analysis to enable complex multi-criteria decision-making for business-critical choices.
AI Agent Factory
Built Smith, an AI agent factory that uses NLP-powered requirements gathering to translate natural language specifications into complete agent configurations. Automatically generates n8n workflow blueprints for agent deployment, streamlining the process from idea to production-ready agent.
Brave Search MCP Server
Built a domain-specific MCP (Model Context Protocol) server integrating Brave Search for web search capabilities within the multi-agent AI platform.
Hummingbot Trading Bot MCP Server
Created an MCP server for managing Hummingbot trading bots. Provides automated trading bot configuration, strategy management, monitoring, and control through the Model Context Protocol.
RAG Pipeline with Document Management
Implemented a full Retrieval-Augmented Generation pipeline with file upload, automatic document categorization, vector search, and auth/RBAC with read-only user support. Powers accurate, context-grounded AI responses across the multi-agent platform.
Aviation Fuel Certificate Registry
Built the frontend for a sustainable aviation fuel certificate registry — issuance, transfer, and retirement flows with i18n, batch operations, and multi-page selection. Employed JSON schema-based forms, SSO integration, and XState-driven user flows for complex certification workflows.
Maritime Emissions Compliance Registry
Developed a maritime emissions registry — vessel tracking, GHG savings calculations, transport work intensity metrics, retirement statement PDF generation, and regulatory compliance views for maritime sustainability certification.
Green Energy Proofs Platform
Led frontend development for a green energy proofs platform — accounts, companies, memberships, holdings, and administrative processes UI. Architected a unified process workflow system, migrating disparate forms into a consistent process-driven architecture. Set up Storybook component library, E2E tests with Playwright, and reproducible dev environments using Nix.
Green Energy Traceability Platform
Built blockchain-integrated green energy traceability dashboards with usage statistics and high-throughput data synchronization. Enabled energy companies and consumers to transparently track green energy production and consumption on-chain.
Distributed Voting Smart Contract
Authored a Solidity smart contract for distributed voting sessions with a whitelist-based node system and configurable majority rules. Implemented vote recording, majority algorithm, and passed a comprehensive security audit.
Decentralized AI Coding Agent
Built an AI coding agent for a decentralized network, solving SWE-bench-style coding problems autonomously. Designed a two-phase agent architecture (analysis then implementation) with intelligent safeguards: import validation, over-engineering detection, scope control, and call chain awareness for duplicate fix prevention. Added polyglot test support and batch test runner infrastructure.
Open-Source Auto-Generated Admin Panel
Maintained a production-ready open-source auto-generated admin panel for Node.js applications. Built framework connectors for Express, NestJS, and Hapi with ORM adapters for Sequelize, MikroORM, TypeORM, and Mongoose. Triaged community issues, reviewed contributions, and shipped new features.
eCommerce Automotive Platform
Built an eCommerce platform for automobile sales with an automated order pipeline — order processing, invoice generation, and administration panel. Integrated third-party CRM, notifications, invoicing, and contracting systems. Implemented MongoDB aggregation pipelines and CI/CD using Cloud Build and Cloud Run on GCP.
Visual Testing Platform
Built a platform for executing E2E tests on remote EC2 instances with video recording and quality metrics assessment. Organized test runners into scenarios executing specific test cases. Full project ownership from requirements gathering through deployment.
REST API for Media Processing
Developed a standalone REST API for efficient image and video processing. Engineered real-time statistics for a call center application, improving performance and data accuracy. Led technical workshops on event sourcing, Apache Kafka, compilers, and AWS services.
Real Estate & Car Listing Aggregator
Full-stack listing aggregator scraping Polish property portals and car marketplaces with anti-bot evasion (Puppeteer stealth, rate limiting, retry logic). Features an interactive map view with pin filtering, radius sliders, and price markers. Includes attractiveness scoring using real transaction data, intelligent duplicate detection, price monitoring, and Stripe subscription management.
Board Game Rules AI Assistant
AI-powered board game knowledge base using hybrid search (BM25 + vector embeddings) for accurate rule retrieval. Features AI chat with tool use, BGG scraping with Playwright fallback, Stripe subscription system, and anonymous user rate limiting.
AI Medical Assistant
Upload medical documents (lab results, PDFs) and chat with AI about health data. Features medical book search with vector embeddings, MRI image analysis, differential diagnosis comparison, and a real data dashboard.
Party Games Platform
Real-time party games platform with multiple Polish game modes (Familiada, Jeden z 10). Features WebSocket-based multiplayer, game state management, and E2E test coverage.
What People Say
What my colleagues and team leaders have to say about working with me.
Jonasz is one of the most dedicated individuals I've worked with. He's involved in virtually every initiative and consistently delivers high-quality solutions. Eager to explore new technologies and trends, including AI, he doesn't recognize the phrase "it can't be done."
Team Leader
Previous Role
Jonasz is one of the best collaborators I've had in my career. He excels on both the frontend and backend, striking the perfect balance between delivering high-quality results and getting things done.
Coworker
Former Colleague
My Tech Stack
Expertise across different technologies and tools I use in my daily work.
Core Technologies
Frontend
AI & Platforms
Infrastructure
Data & Architecture
Talks & Articles
Sharing knowledge through technical talks and written content.
Event Sourcing Introduction
Delivered an introductory talk on event sourcing, covering event streams, event stores, state retrieval from events, optimizations with snapshots, event versioning, and solutions for handling multiple event versions. Created JavaScript repository with exercises to get familiar with event sourcing and EventStoreDB.
Creating Node.js Admin Panel in 7 Minutes
Presented a talk on setting up an administration panel for Node.js applications using the AdminJS library and MongoDB adapter.
Kafka Introduction
Authored an article introducing Kafka and its core concepts for distributed systems.
How do Compilers Work?
Discussed the workings of compilers. Talk focused on TypeScript internals and low-level implementation of compilers and transpilers.
Batching Smart Contract Calls in Nest.js Apps
Article describes solutions for managing multiple blockchain calls inside Node.js backends and executing transactions in parallel using one wallet.
Sequential Events Execution
Published an article detailing best practices for executing actions in Node.js backends that require calls to services from multiple domains. Covered strategies to avoid circular dependencies and ensure transactional success using the "sequential-events" library for NestJS.
Best Practices for Setting up HardHat Projects
Wrote an article outlining best practices for configuring HardHat projects. Discussed recommended approaches for creating user-friendly functions for open-source projects and provided a sample TypeScript configuration for project execution.
Education
My academic background and formal education in computer science.
Wroclaw University of Science and Technology
Computer Science · Wroclaw, Poland
Additional Courses & Certifications
DeepLearning.AI Specializations
Completed comprehensive specializations from DeepLearning.AI, founded by Andrew Ng. These industry-recognized certifications demonstrate expertise in cutting-edge AI technologies and practical implementation skills for real-world applications.
Architect's Path
Completed the comprehensive "Droga Nowoczesnego Architekta" (Path of the Modern Architect) program, gaining practical knowledge of Domain-Driven Design (DDD), Event Sourcing, microservices architecture, business communication strategies, and legacy system modernization techniques. This intensive program focused on developing architectural thinking and implementing modern software design patterns.
AI_devs 3
Participated in an advanced AI development program focused on practical implementation of AI agents, prompt engineering, and model optimization. This intensive course covered the latest techniques in AI development and deployment strategies.
Organizations
Contributions to charitable and educational organizations.
Software Engineer
Contributed to the development of a donation platform for a charity organization. The platform enables the setup of donation goals, fosters donor competition, and facilitates progress sharing.
JavaScript Mentor
Mentored computer science students in the creation of a marketplace application for the Board of European Students of Technology. The application served as a platform for sourcing materials needed to conduct competitions.