Piotr Krawczyk
Verified Expert in Engineering
Software Developer
Warsaw, Poland
Toptal member since April 27, 2021
Piotr is a passionate software engineer, architect, and technical leader with over 18 years of experience. He has worked on various projects, from early-stage startup applications to complex multi-tier large-scale systems. His expertise covers cloud architecture, back-end development, AI-driven analytics, and engineering leadership. Piotr is skilled in technologies like AWS, Java, Node.js, React, and PostgreSQL, and he has a strong command of modern web frameworks and robust cloud platforms.
Portfolio
Experience
- Java - 18 years
- JavaScript - 18 years
- PostgreSQL - 18 years
- Full-stack - 15 years
- TypeScript - 7 years
- Node.js - 7 years
- Machine Learning - 6 years
- React - 5 years
Preferred Environment
Jira, Git, IntelliJ IDEA, Linux
The most amazing...
...experience I've had was developing an application that won 1st prize at Future Cities Satellite Oslo Hackathon.
Work Experience
Principal Engineer
Solvemed
- Built and scaled production infrastructure supporting 8 healthcare systems, providing a reliable and secure foundation for Solvemed’s mobile pupil-reactivity measurement platform.
- Designed and implemented Epic integration from the ground up, enabling Solvemed to integrate with Epic-based healthcare environments and support clinical workflows without relying on an existing integration framework.
- Developed and maintained back-end and DevOps infrastructure for a healthcare product, ensuring reliable communication between the mobile application, back-end services, and healthcare-system integrations in a production environment.
Principal Engineer
WorkHQ
- Architected the design for a newly developed platform, ensuring scalability, reliability, and alignment with business objectives.
- Integrated AI-driven capabilities by incorporating large language models (LLMs), enabling users to perform advanced query tasks through AI-powered interactions.
- Redesigned the data layer using the Medallion architecture, optimizing data management processes and enhancing overall system performance and reliability.
- Introduced a workflow-based approach and led the refactoring of legacy code, streamlining development processes and improving system efficiency.
Senior Back-end Engineer
Prysm Financial Technology Inc
- Executed a seamless integration with a banking-as-a-service (BaaS) provider, enhancing platform capabilities and streamlining user access to financial services.
- Transitioned legacy code to a workflow-based architecture, improving system efficiency and scalability.
- Played a pivotal role in rapidly developing the platform within six months, meeting aggressive timelines, and establishing a robust foundation for future growth.
Lead Back-end Engineer
Complion
- Developed a new "study management" module using React on the front end and Node.js on the back end of the application.
- Guided a team of five developers and provided the team with best practices.
- Designed and developed a GraphQL API to support better synchronization between the business and developers.
CTO
Orbitile
- Architected and implemented a scalable system that seamlessly integrated real-time satellite imagery data processors with web applications.
- Led the development of the Orbitile AGRO and Orbitile Power web applications, driving innovation and ensuring robust performance.
- Engineered a cutting-edge AI classification algorithm, enhancing tree recognition accuracy by over 15%.
- Designed and implemented a dedicated data analysis tool to compare the performance of machine learning algorithms in computer vision. Ran over 4,000 experiments to determine which algorithm best defines given terrain classes.
Technical Team Lead
Efinity
- Performed front-end technology migration from GWT to Angular on a highly complex insurance-management system deployed in 14 countries. Used Angular, RxJS, and Bootstrap to implement a new front end.
- Implemented a new claims management module for an insurance company, using Java, Spring, Hibernate, and PostgreSQL. We incorporated the module into two additional systems.
- Provided support and leadership for a team of 15 developers. Helped team members grow within the company by providing regular feedback on their performance.
- Conducted code review to ensure the work delivered by the team was of high-quality standards.
Maintenance Team Lead
Efinity
- Provided support and leadership in critical production, support-issue resolution.
- Conducted code review to ensure the work delivered by the team was of high-quality standards.
- Worked with a business department to prioritize production-issue resolution.
- Created a unique Jira workflow and dashboards to improve the software-development maintenance process.
Technical Team Leader
Efinity
- Designed an architecture for a multi-insurance compare and sell platform application that integrates over 30 insurance companies.
- Implemented key application components, contributing hands-on expertise to the project's critical areas.
- Conducted code reviews to ensure that the work delivered by the team was of high-quality standards.
- Managed and supported a team of six developers, providing technical leadership, guidance, and task prioritization.
Senior Java Developer
Leadenhall Polska
- Designed the architecture and implemented a completely new front-end framework for an insurance management system that operates in 14 countries and produces 3+ million quotes annually.
- Implemented key features in the back end of an insurance management system.
- Integrated a new system with the existing core platform.
Java Developer
Efinity
- Implemented back-end logic for one of the first B2C car insurance comparison systems on the market that integrated over 10 insurance companies.
- Integrated with insurance companies' calculation and comparison modules.
- Introduced and advocated for the adoption of jQuery technology in the company and developed a front end for the insurance comparison system.
- Conducted a series of technical seminars related to front-end technologies.
Java and J2ME Developer
TLS-Technologie sp. z o.o
- Implemented the back-end logic for mobile services and content platforms for the mobile network operator.
- Implemented several mobile applications (Texas Holdem, Sudoku, and Kakuro).
- Managed a small team of three developers while creating mobile applications.
Experience
Satellite Data-driven Platform to Analyze Greenery Growth Under Power Grids
I developed all the back- and front-end logic for this project using the Angular, Node.js, TypeScript, NestJS, GraphQL stack. I also automatized machine learning processes and put them into the infrastructure.
Satellite Data-driven Platform to Monitor Land Leaseholder Activity
I developed all back- and front-end logic for this project using Angular, TypeScript, Node.js, NestJS, TypeORM, and PostgreSQL. I also automated machine learning processes and added them to the infrastructure.
Web Application for Agricultural Insurers
I developed all back- and front-end logic for this project using the React, Node.js, TypeScript, NestJS, and REST API stack. I also deployed the application in the infrastructure.
Agricultural Claim Detector
Forex Bot
Chess bot
Education
Master's Degree in Computer Science
University of Warsaw - Warsaw, Poland
Bachelor's Degree in Mathematics
University of Warsaw - Warsaw, Poland
Certifications
Graph Developer - Associate
Apollo GraphQL
Machine Learning
Stanford University | via Coursera
Convolutional Neural Networks in TensorFlow
Coursera
Improving Deep Neural Networks: Hyperparameter tuning, Regularization and Optimization
Coursera
Structuring Machine Learning Projects
Coursera
Convolutional Neural Networks
Coursera
Skills
Libraries/APIs
Node.js, REST APIs, React, TensorFlow, jQuery, RxJS, Leaflet, Keras, Pandas, Scikit-learn, NumPy, NgRx, Passport.js, Google Maps API, NgRx/store, PyTorch, Terragrunt
Tools
Git, IntelliJ IDEA, Jira, Apache Maven, Bitbucket, Jetty, Atlassian, Figma, WebLogicServer, Apache Tomcat, Eclipse IDE, Subversion (SVN), Bamboo, Mercurial, GitLab, Atlassian SDK, Sequelize, Terraform, React Apollo, Amazon Simple Queue Service (SQS), Amazon Simple Notification Service (SNS), Apache Airflow, Amazon OpenSearch, Kubectl, AWS SDK, CircleCI
Languages
Python, Java, TypeScript, HTML, JavaScript, SQL, GraphQL, CSS, Java 8, TypeScript 3, Java 9, HTML5, CSS3, Kotlin, XML, Groovy, C++
Frameworks
Spring, NestJS, Jest, Angular, Hibernate, GWT, Mockito, JUnit, AngularJS, Selenium, Angular Material, Redux, Express.js, Bootstrap, Next.js, Apache Struts, Jakarta Server Pages (JSP), Ant Design, XMLBeans, JPA, JSON Web Tokens (JWT), Spring Boot, Flask, Apache Spark
Paradigms
Object-oriented Programming (OOP), Scrum, Functional Programming, Agile, Model View Presenter (MVP), Continuous Integration (CI), REST, Test-driven Development (TDD), Unit Testing, RESTful Development, Web Architecture, Continuous Delivery (CD), Microservices, Microservices Architecture, Serverless Architecture
Platforms
Linux, MacOS, JEE, Amazon Web Services (AWS), AWS Lambda, J2ME, JBoss, Google Cloud Platform (GCP), Docker, Azure, Kubernetes, Apache Kafka, MetaTrader 5
Storage
PostgreSQL, JSON, MongoDB, PostGIS, Google Cloud, MySQL
Industry Expertise
Insurance
Other
Algorithms, TypeORM, Back-end, Full-stack, Technical Leadership, APIs, Architecture, Software Architecture, Web Development, Software Design, OpenAI, Artificial Intelligence (AI), System Architecture, CTO, Full-stack Development, AI Architecture, AI Engineering, Machine Learning, Convolutional Neural Networks (CNNs), Integration Testing, HTTP, Selenium IDE, Hibernate 3, Team Leadership, Front-end, Geolocation, GeoJSON, Deep Neural Networks (DNNs), Neural Networks, Mathematics, Leadership, User Experience (UX), User Interface (UI), Security, Apollo, Data Science, Cloud, Serverless, Algorithmic Trading, Cloud Infrastructure, Team Leadership & Supervision, Computer Networking, Low-level Programming, Hardware Design, Evolutionary Algorithms, Network Protocols, Cryptography, Statistics, Probability Theory, Calculus, XML Web Services, Web Services, Startups, Early-stage Startups, Agrotech, Energy Monitoring, Data Scraping, Encryption, Optimization, Enterprise Java Beans (EJB), Apollo Server, Fintech, Temporal.io, Large Language Models (LLMs), Bots, Forex Trading, Hugging Face, Natural Language Processing (NLP), GitHub Actions, WebSockets, Cloud Architecture, Server Infrastructure, Finance, Compliance, SOC 2, Agile Leadership
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