// hello, world
Maciej Kwaśniak_
Frontend Architect · Devtooling & DX @ CrowdStrike
Costa del Sol, Spain · 14 years of experience
[email protected] · linkedin.com/in/macsour · github.com/exelord
Frontend architect with over 14 years of experience delivering web applications at scale. I lead cross-team initiatives that improve developer productivity, define engineering standards, and modernize legacy systems. My work spans CI/CD pipeline optimization, monorepo architecture, design systems, and building delivery platforms that support hundreds of engineers.
Beyond product work, I design framework-level libraries, internal tooling, and reusable systems that raise the quality bar across engineering organizations. Creator of 30+ open-source packages with 1000+ combined GitHub stars.
Engineering is not just my job, it's my passion.
"I think Maciej is a rare developer. Incredibly skilled, customer-centric, a leader and someone who contributes to a good team spirit. If I ever get the chance again I will hire him on the spot."
"Maciej is a brilliant frontend engineer. He positively surprised me with his passion for UX, always having users' best interest in mind and being able to lead initiatives and projects. A true asset to any team."
"Maciej is the best Ember developer I've worked with. He has extensive experience in Ruby and Rails, making him capable of delivering complete solutions. He definitely cares about long-term, well-architected solutions built to last."
"Maciej is a highly talented engineer who is fluent in Javascript as well as UI/UX. He contributed as a mentor, lead, and an excellent team player to improving our project's code quality."
"One of the most talented persons I know. Remarkable creativity, determination and passion for whatever he is doing. Thanks to his out of the box thinking we were able to solve complex challenges in a smart and elegant way."
"Maciej is an exceptional developer:passionate and hard working with a broad scope of experience. He remembers the whole picture and recalls the details. High quality is part of his nature."
"Maciej is not only technical, but also business-oriented. I really like his sane approach and accurate observations. I really recommend working with him."
"A very skilled developer with a strong focus on quality and well-architected software. I would very highly recommend him to anyone looking for beautiful solutions to complex problems."
"A great person and a remarkable tech leader. Besides having expertise in Ember.js and JavaScript, he has a ton of skills to contribute to the product. Always up-to-date and capable of implementing outstanding solutions."
"A multi-talented developer with huge knowledge in Ember.js and Ruby on Rails. His passion for programming and ability to share knowledge in an interesting way inspired me to try and learn Ember."
"Great initiative, exceeding the standards. He brings a different perspective to problem-solving both on the business and user-interface side. A perfectionist in everything he does."
"He helped us push our quality always higher, but was also reasonable about it, understanding that the perfect solution is always relative. His experience in organizing developers work was very useful."
"Always looking to exceed expectations. His critical mindset guarantees top quality and bug free software, loved by our users. Maciej played a key role in growing 9teams to the mature solution it is now."
▸ I have helped companies like
Global cybersecurity leader protecting endpoints, cloud workloads, and identities
Led cross-team initiatives to define engineering standards and shape technical strategy. Redesigned CI/CD pipelines and built a scalable monorepo foundation to improve developer productivity. Designed a new delivery and distribution platform for web applications. Drove tech stack modernization and migration from legacy systems. Mentored team members
Experience management platform powered by NPS and AI
Defined the architecture vision and technical roadmap. Established shared code quality packages to standardize development across the organization. Reorganized QA processes. Audited the application and redesigned architecture, improving bundling, security, and performance. Founded a Community of Practice with working groups. Mentored team members
European all-in-one business finance solution for SMEs and freelancers
Designed and implemented a permission-based access control system with dynamic role definitions. Drove architecture decisions and established development standards. Mentored team members
Germany's leading digital insurance manager
Led architecture decisions and mentored the team. Designed a state-machine-driven flow engine for multi-step forms, a data fetching layer with stale-while-revalidate caching and automatic garbage collection, and a forms management system with proxy-based value binding, async validation, and decorator-based field registration. Built reusable UI component addons including shell navigation and an icon library
Unified online payment solutions and fraud prevention platform
Led the team and established development standards. Designed the frontend architecture and built reusable internal libraries with layered domain models, extensible validation, and composable UI components. Built a design system. Reworked CI/CD pipelines. Mentored team members
Ember.js consulting firm and creators of the Kurier.js framework
Developed a Node.js JSONAPI server framework (Kurier.js) and provided Ember.js consulting services
Vacation rental management platform connecting property managers with booking channels
Designed the API communication layer and built a design system with internal addons. Implemented a dynamic permission system that auto-generates fine-grained access checks from data schemas, and a reusable authorization and navigation framework. Developed Ember.js applications covering bookings, guests, rentals, messaging, reviews, and financials
RegTech platform for compliance and risk management
Designed frontend architecture, established best practices, and reduced tech debt by standardizing development patterns
Cloud solution accelerating SAP implementation and support processes
Led frontend development and drove a full rewrite of a multi-tenant system into Ember.js with JSONAPI, covering project management dashboards, task and issue tracking, document generation, scenario planning, and team collaboration. Built the Ruby on Rails API server with hierarchical role-based access control, an advanced authentication system, full-text search, a polymorphic diff engine for audit trails, and custom resource-level authorization
Software house specializing in web application development
Developed multiple Ember.js applications for clients across different domains. Recruited and mentored new team members, helping grow the engineering team. Led the local Ember.js community by organizing meetups and giving talks
Built marketing websites, landing pages, and a white-label e-commerce system for online shops. Designed and implemented an offline tournament management system for the Malec Challenge Cup, the biggest unofficial EA FIFA tournament in Poland
▸ Libraries, frameworks, and tools across Solid.js, Ember.js, Ruby, and more
- Oct 12, 2020
Stay away from everyone. The PoC is working! I got rid of MobX and introduced custom tracking layer.
- Sep 28, 2020
Weeklies have been migrated to my own website. Big thanks to sweetbatat for doing this!
- Aug 31, 2020
Updated to latest version, refactored, and prepared for adding a built-in caching layer
- Aug 17, 2020
Git Commits now has the avatar cache (less requests, fastest avatars load). Now it shows 30 commits by default in a list, and display Empty message wh
- Aug 3, 2020
My new website (wip) got a Projects page. Take a look at things I've been working on during last 5 years