Patryk Matuszewski
Verified Expert in Engineering
Software Developer
Wrocław, Poland
Toptal member since February 11, 2014
Patryk is a software engineer who loves creating new things. He develops efficient solutions to meet client requirements. He enjoys helping clients come up with clear visions of their needs. Patryk loves to make the whole development process clear and efficient, implementing the best available options for a specific problem—he has experience using approaches like continuous delivery, Scrum, TDD, ATTD, BDD, and extreme programming.
Portfolio
Experience
Availability
Preferred Environment
MacOS, Android Studio, IntelliJ IDEA
The most amazing...
...project I've worked on is the back end of the biggest worldwide VOD delivery company.
Work Experience
Lead Engineer | Blockchain Developer
Motobloq.com
- Developed a production-ready solution for car collectors.
- Collaborated closely with the client to manage dynamic changing requirements and implement them.
- Helped back-end and front-end engineers to achieve the team goals in the best possible way.
- Designed and implemented the event-driven architecture suitable for integrations with multiple blockchains. Contributed to various system modules and coordinated them to deliver business value.
- Provided blockchain cutting-edge solutions to deliver the easiest possible UX for end-users. Integrated with Ethereum Mainnet to allow bridging tokens between the networks.
Blockchain Developer
Blockchain Client (NDA)
- Developed a prototype solution for managing company bonds using blockchain technology on Polygon. Technology stack: Next.js, TypeScript, Solidity, HardHat, Polygon, GraphQL, PostgreSQL, Redis.
- Used an external custody wallet management system (Fireblocks) to integrate with the application, simplifying onboarding for non-crypto users.
- Utilized Account Abstraction (by Accountkit.alchemy.com) to create more extensible account management, enabling further integrations such as KYC and sub-accounts. It offers a more seamless user experience and customizable managing accounts.
- Created a blockchain indexer (based on Subsquid.io) to process important information in near real-time, which was then used to display portfolio details for logged-in users.
Blockchain Wallet Engineer (via Toptal)
GiftXD, LLC
- Created a module that enables transaction management for users' wallets on a gift card marketplace.
- Integrated with Fireblocks' external custody keys management system.
- Developed a robust system that utilizes TypeScript, PostgreSQL, and BullMQ to handle a vast volume of user transactions concurrently.
- Collaborated closely with the team members to successfully integrate the module with an existing system.
Software Data Engineer
Accent Technologies Inc.
- Improved and maintained the extractor module to handle millions of emails per day.
- Reduced operation cost of the extractor module by an order of magnitude.
- Worked closely with the business team to improve the business value by implementing new features.
- Helped to improve the performance and stability of the data analytics module (PySpark).
Team Lead
Toptal Client (Gaming Industry)
- Gathered and analyzed business requirements during the iterative process.
- Led and managed a team of six people. Worked closely with the client and PM to define the most effective development process.
- Worked closely with other verticals (QA and design) to create a coherent vision of the project.
- Wrote the integration layer between the React app and the blockchain and created an authentic gaming experience for customers.
Lead Developer
Toptal Client (NDA)
- Gathered and analyzed requirements with the client.
- Helped organize the project timeline by introducing Agile methods.
- Worked closely with the front-end team to help integrate with the back end.
- Planned and implemented the sync layer between the back-end application and Ethereum private network, which helped query data from the blockchain, using simple MongoDB queries.
- Planned and implemented the back-end service, which was the gateway between the Ethereum network and the application—used an event-driven approach with Spring Cloud and Kafka solutions.
Senior Blockchain Engineer
Coinbooth
- Created an integration layer in Node.js with the BitcoinCash network.
- Analyzed and gathered requirements with the client for a payphone-like application.
- Created the application's design and architecture and implemented them in the working prototype.
- Designed the REST API, which different types of clients could have used.
- Analyzed and made plans for the future development of the application.
Senior Blockchain Engineer
Synkt Games
- Worked closely with the client on the white paper, and proposed improvements to the economic model.
- Implemented a Crowdsale contract for the project.
- Implemented ERC20 and utility smart contracts for the project.
- Created the full test suite for the codebase (Truffle).
- Deployed and tested smart contracts in the private blockchain.
Software Engineer
AiCure
- Created a flexible solution to generate questionnaires from data taken from external sources.
- Implemented an audio/video framework for further integration with the company's AI system.
- Worked closely with team members to gather business requirements and transform them into application features.
- Researched Google Fit abilities which could be used to improve application usability.
- Worked on the application's architecture and provided detailed feedback.
Technical Project Lead
Castling.in
- Initialized and analyzed the business elements of a real-time web-based game project for the education sector.
- Created and realized the plan of development using an iterative approach and tight communication with the client.
- Analyzed and eliminated all risks and proposed the scope which gave the best outcome for the client.
- Used highly efficient approaches (Akka, Microservices, Cassandra) to meet real-time requirements and supported multiple teams playing at the same time.
- Proposed and implemented event sourcing architecture for the system, which generated new tools and brought about high fault tolerance and improved performance.
Back-end Lead Developer
Toptal Client
- Prepared and implemented scalable architecture from scratch.
- Implemented an efficient scrum planning process in the project.
- Worked as scrum master and tried to help the rest of the team understand Scrum processes.
- Created the continuous deployment environment by implementing full automatic regression testing suites.
- Helped to analyze and understand all business concerns and how they impact the final product.
Lead Software Developer
Snaptype
- Elicited client requirements, prepared the project plan, and helped analyze all business requirements/rules.
- Created the UI/UX of the application based on existing iOS design, considering Material Design guidelines.
- Implemented an effective drawing screen solution which is easy to use for kids.
- Created a sufficient automatic testing solution, which used remote real devices to provide the best testing results for application use cases.
- Published the application in the Play Store with two versions and minimum defect level, supporting the greatest possible number of devices and quickly resolving any existing issues.
Software Engineer
5AM Solutions
- Helped to set up BDD strategy for an extensive testing environment.
- Worked on microservices to create clear and consistent endpoint contracts.
- Helped implement a data service to handle a massive amount of ingoing data using cloud solutions.
- Used Spring templates and Feign to create communication channels between different microservices.
- Worked on a Spring Cloud configuration to achieve the best fault tolerance and availability level under conditions specific to the domain model.
Android Developer
AnyApp.mobi
- Improved application quality by finding and resolving most critical issues.
- Introduced Scrum processes.
- Helped to understand how the software development process should look and started implementing a solution tailored for this specific startup project.
- Collaborated with back-end developers to find the best options to achieve best performance from mobile and server perspectives.
- Helped to find a business model and how to grab customers.
Back-end Lead Developer
Uluvit.com
- Prepared and implemented scalable architecture from scratch.
- Implemented an efficient scrum planning process in the project.
- Assisted in finding and analyzing all business concerns.
- Worked with mobile developers to achieve the best performance from the server side.
- Used TDD and created a base for BDD to have a fully-integrated deployment environment.
Software Engineer
Airline Company [NDA]
- Created a robust architecture for a ticket management application for the company's customers.
- Assisted in improving the Scrum process and was a proactive member during standups.
- Helped with business analysis and worked closely with the client.
- Worked and communicated in an international team in the client's workplace (abroad).
- Implemented and released the app used by over 100,000 people worldwide.
Software Engineer
VOD Content Delivery Company
- Integrated third-party platforms with the system by VXSLs.
- Wrote unit/integration tests.
- Maintained the existing codebase.
- Discussed and proposed new solutions.
- Fixed critical bugs.
Software Engineer
VD.pl
- Created an integral SEO system to support existing customers.
- Maintained existing solutions.
- Helped to create a clear vision what should be done in the future.
- Learned and worked in unknown previously technologies to created better solutions (no silver bullets).
- Worked with other people in the team to achieve common goals.
Experience
Blockchain IoT
https://github.com/blockchain-IoT/blockchain-IoT-coreAtomize Software Spin Framework
StreetAd.pl | Startup
- Led a four member team.
- Handled business analysis for the project.
- Made pitches for investors.
- Implemented the back-end using cutting-edge technologies (Symfony 2, PHP 5.3, MongoDB).
- Created a suite of full automatic acceptance/unit tests (Behat, PHPUnit).
- Implemented a mobile client (Android SDK 2.3).
Newspaper Mobile App in Android
To achieve that, we improved the automation testing process (added more unit tests, fixed existing one), fixed all memory management issues (like invalid bitmap processing, lack resources cleaning) and identified all use cases which can cause problems. At the end of the project, the number of crashes were reduced about 70-80% and the app started getting more positive reviews in Google Play Store.
Internal Software for an Audit Company (Android 3.0)
- The application contains questionnaires that are created dynamically by a server-side application and are needed to implement an optimal solution to exchange data between a server and web application.
- I needed to create a robust software architecture to support multiple pages and dynamic views with extensive user input support (open, close, multiple-choice question, and camera support) and multimedia support (video player, etc.)
- I implemented support for many types of tablets (Samsung, Sony, Asus).
VOD Software
Technologies: Java SE, JEE, Spring, XML, XSLT
Umowiony.pl
- Led a three person team.
- Conducted business analyses with the customer (created a list of features, wireframes, and a domain model).
- Prepared a specification of a back-end API that was needed to communicate between an Android app and a back-end server (used RESTful best practices).
- Handled project management using Agile methodology and TDD.
- Implemented the application using cutting-edge Android technologies (API 4.1, AndroidAnnotations, RoboGuice, Robolectric).
Software for Analyzing Mobile Application Stats | PHP 5
- I implemented a library to communicate with a back-end API for J2ME. It featured optimized operations for low-memory devices and support for a wide range of mobile phones.
- I created a MySQL sharding module for a back-end system (PHP 5.3, MySQL). It required a scaling feature for a growing numbers of users and applications.
- I implemented a dynamic web interface on the user side (stats are updated in almost real-time).
Leagues Management Application (PHP)
• Architected the app
• Deployed a small iterative process to control requirements changes
• Implemented the app based on the project and client requirements
• Set up a production environment (Apache 2, PHP FPM, ACL, MySQL)
Technologies: PHP 5.3 + Doctrine + Zend Framework 1 + Facebook API, jQuery, PHPUnit
Tax Refund Management Application
- Worked directly with the client to settle all requirements
- Implemented a small iterative development process to handle changes
- Architected the app
- Implemented the app based on existing law regulations
- Set up a production environment (Apache 2, Nginx, PHP FPM, MySQL)
Technologies: PHP 5.3 + Doctrine 2 + Zend Framework 1 +
Doctrine 2 + Zend Framework 1 + jQuery + PHPUnit
BlackBerry 6 Project
- The UI implementation (JavaScript, HTML) is based on existing wireframes and included support for many types of devices.
- I created a library to communicate with Facebook API in Java 1.4. I needed to use a limited edition of Java specifications to create a robust solution to support many user behaviors, such as image uploading, adding texts to the Wall, inviting friends, and sending messages to friends. The application worked on 3G.
Android 2.2 Project
Education
Bachelor's Degree in Computer Science
Polish-Japanese Academy of Information Technology - Warsaw
Skills
Libraries/APIs
Java, API, React.js, Node.js, Java, React.js, Java Message Service (JMS), Doctrine, RxJava, Web3j, Hystrix, Backbone.js, Facebook API, jQuery, X (formerly Twitter) API, PySpark
Tools
PhpStorm, IntelliJ IDEA, Calabash, Jenkins, RabbitMQ, Remix IDE, Eureka, Apache ZooKeeper, Eclipse IDE, JHipster, Android, WebStorm, Amazon Elastic Container Service (ECS), Firebug
Languages
JavaScript, Solidity, Java, Kotlin, TypeScript, Java SE, XSLT, PHP, C#, Java, Scala, Python, PHP, SQL, Clojure, GraphQL, Go
Frameworks
Spring Security, Truffle, Android SDK, Spring Boot, Spring, Swagger, Android, Next.js, Spring, JUnit, JBehave, Robolectric, Dagger, Zend Framework, PHPUnit, Espresso, Akka, Redux, AngularJS, JPA, JavaServer Faces, Hibernate, Spark, Flask, Hardhat
Paradigms
Continuous Integration (CI), Agile Development, Iterative Programming, Agile Development, Object-oriented Programming (OOP), Unit Testing, Design Patterns, Agile Development, Functional Programming, Cross-Platform, Microservices Development, Concurrent Programming, Distributed Programming, Pair Programming, Domain-driven Development, Mobile App Design, Agile Development, Event-driven Programming, Event-driven Architecture, Asynchronous Programming
Platforms
Blockchain, Blockchain, Ethereum, iOS, Google App Engine, Android, Linux, Chainlink, MacOS, Java EE, Java EE, Apache Kafka, Zeppelin, Kubernetes, Docker, Netflix, AWS, Windows Development
Storage
Redis, MySQL, MongoDB, NoSQL, Cassandra, PostgreSQL, Google Cloud Development, Amazon S3, Elasticsearch, Memcached, Data Lakes
Other
Ethereum Smart Contract, Architecture, Technical Leadership, Web Development, Full-stack, Front-end Development, Cryptocurrency, Back-end Developers, Spring, Software Architecture, Decentralized Finance (DeFi), Annotations, Material Design, WebSockets, Google Fit, Quorum, Bitcoin, Web 3.0, Netflix OSS, Apache Commons, Apollo, Apollo Server, Leadership, Know Your Customer (KYC), Tokenization, Web3, Off-chain Development, ERC-20, Cryptocurrency Wallets, Ledgers, BullMQ, ERC-721, Polygon, Account Abstraction, UTXO, Software Engineering, Data Engineering, Data Science
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