Jarek Lipski
Verified Expert in Engineering
Software Developer
Jarek is a full-stack developer with more than 15 years of experience. He currently specializes in Vue, Node.js, and Firebase, as well as Flask, Django, and Ruby on Rails development. Throughout his career, he has worked in various industries in different roles: cloud operations specialist, back-end developer, front-end developer, team leader, and scrum master. In his spare time, Jarek is an open-source contributor and tech blogger.
Portfolio
Experience
Availability
Preferred Environment
Amazon Web Services (AWS), Firebase, Docker, Node.js, Vue, Nuxt.js, Python, Flask, JavaScript, Ruby on Rails (RoR)
The most amazing...
...project I've built is a conference companion progressive web application used by hundreds of people during FOSDEM.
Work Experience
Senior Full-stack Engineer
ChartMogul
- Added a CRM functionality to the subscription analytics platform.
- Developed subscription cancellation management with Brightback.
- Learned Ruby and Ruby on Rails while developing a complex application and completed several online courses (Pragmatic Studio and RubyMonk).
Front-end Developer
Legrand
- Developed multilingual terms and conditions and privacy policy pages used in multiple regions and across all products, including web, mobile, and shop.
- Enabled the recording of the user's consent in the database.
- Added a feature to legal documents, allowing them to be versioned and previewed before deployment.
Web Developer
WeMaintain
- Developed a brand new company website from scratch, containing custom components, like timeline, sliders, and others.
- Built the website to include four regional variants. Synchronization is done in an optimized manner to avoid duplication while maintaining flexibility for regional teams.
- Built the styles and symbols so that the client can manage the content autonomously via Webflow Editor without touching the code or via CMS.
- Migrated a fully functional blog from an existing blogging platform to the website. The content is managed via CMS, like posts, categories, authors, and others.
- Integrated website with Salesforce CRM. Added custom Typeform forms. Configured analytics and A/B testing experiments.
Full-stack Developer
Netvideo
- Architected and developed a complete webinar platform (landing page builder, back office, authentication, polls) used by thousands of participants per event.
- Built interactive moderation and analytics dashboards for the application.
- Developed a fully configurable reporting system (operator can choose columns and their types, cross-reference data collections), generating personalized spreadsheets (users, connections, polls) based on raw data from various sources.
Full-stack Developer
Netatmo
- Developed the marketing back office from scratch for the transverse growth team.
- Delivered personalized news and push notifications to over a million users worldwide.
- Helped the team successfully launch large targeted marketing campaigns, resolving issues with mobile platforms and payment providers.
Front-end Developer
Viking Sasquatch
- Built front end for pricing engine for the insurance industry. The user interface is fully responsive and offers custom forms and components adapted to the user's needs (price entry, rates and fees calculation, charts, location selection, and more).
- Helped to recruit, train, and review the work of two younger colleagues.
- Advised on the progressive web app (PWA) features to be used in the application.
Front-end Developer
Bolt Threads
- Developed heavily customized eCommerce solution in distributed team.
Senior Application Developer
Jahia
- Developed personalization and A/B testing solution for enterprise CMS.
Tech Lead
Netseenergy/EDF Group
- Worked on a microservice migration project for a company in energy efficiency for business and institutional clients sector.
- Helped to popularize Agile methodology and software engineering best practices, such as test-driven development (TDD), pair programming, and others.
- Participated in architecture committee meetings to discuss the new data pipeline and microservice platform.
Developer
Artset
- Developed an application for art galleries, including the back end, web app, and mobile app.
- Developed a specialized billing module for art galleries.
- Configured and ran a cloud infrastructure on AWS.
- Developed CRM module—artist biography, sending catalogs to clients, and export.
Consultant Software Developer
GS1 / Xebia France
- Developed web-based product barcode management solution.
- Developed various back-end systems and APIs (Node.js, Java, Python) and front-end interface (Angular 2).
- Managed cloud infrastructure (AWS EBS, EC2, DynamoDB, Lambda, S3, CloudFront, Route53).
- Developed efficient Global Trade Item Number (GTIN) generation algorithm (Node.js, Elasticsearch).
- Presented an introductory talk about Kanban during an internal company conference.
Scrum Master | Software Developer
Ullink
- Developed a middle office solution that allows the management of trade allocations, confirmations, and fees for stock market brokerage firms.
- Worked as a part-time scrum master, facilitating the work of a team and helping to improve its development process, focusing on functional user stories, reducing WIP, promoting frequent releases, and initiating collaboration across departments.
- Developed a client-server application used by big financial institutions (Java, C#, OSGi, IKVM, AssertJ, XML, Gradle).
- Won ShipIt Day team contest, developing a FIX-based post-trade matching solution in 24 hours. Co-organized Ultimate Bug Fighting Championship.
- Interviewed candidates for scrum master and back-end developer roles.
- Promoted Linux in the company by creating and adapting tools, organizing meetups, and maintaining chat channels.
Software Developer
Viadeo
- Developed back-end services for API, platform, and mobile teams in a professional social network company with over 50 million worldwide users.
- Worked with Scrum and Kanban agile development processes and participated in their refinement in a cross-functional team, complete with front- and back-end developers, operations, product, and marketing.
- Developed a public RESTful API that handles up to 1 million requests per hour.
- Participated in the development of a brand new service platform under the direct supervision of the architecture team (CQRS, DDD).
- Implemented a search company into user network functionality (Elasticsearch, Java, Guava, Spring, Cucumber) and address book synchronization, search members by phone number, and job offer suggestions service (Elasticsearch, Java, Spring, Cucumber).
- Helped to organize the Viadeo API London Hackday event.
- Temporarily managed the team during the project manager's absence. Responsibilities included planning to meet internal project deadlines, dealing with customer requests, and facilitating inter-team collaboration.
Software Engineer
Wood Group Intetech
- Developed Intetech Well Integrity Toolkit (iWIT) web application for the oil and gas industry in a team of 11 programmers.
- Redesigned the data source abstraction layer communicating with Oracle, MS SQL Server, web services, PI, and IP2 DBs.
- Implemented well structure recognition algorithm, reports, and data entry pages.
- Developed and troubleshot a web service for synchronizing data with a large customer system (JAXWS, JAXB, XML Schema).
- Introduced Log4J logging framework into the application; configured, wrote extensions, documented and trained others on how to use it, created RSS feed from the application log for testers.
- Updated the database structure, implemented stored procedures and triggers (Oracle, SQL, PL/SQL).
- Remotely deployed, configured, troubleshot and profiled iWIT web application on customer test and production virtual servers.
Software Developer
CST Technobank
- Maintained the web framework which provided fundamental functionality to all the company's products for financial institutions.
- Implemented various framework modules including authorization and authentication, file repository, and tracking.
- Supervised two student interns developing SSO module.
- Created user interface widgets, for example, file explorer, panel, and tree that support all major web browsers.
- Redesigned and reimplemented various components including a controller with centralised input validation and error handling, business logic and internationalization.
Software Developer
POLENG
- Co-created a translation memory management web application in a small team within a company specializing in rule-based machine translation.
- Designed and implemented a bilingual text alignment algorithm (subject of my Master's Thesis) and a rule-based sentence splitting algorithm (rules stored using SRX standard).
- Created a user interface, controller, data access layer, and installation scripts.
- Implemented a translator web service.
Demonstrator
Adam Mickiewicz University
- Worked as a teaching assistant and provided help and support to younger students during practical classes.
Intern
Accenture
- Helped to organize the work environment for developers on a project at a customer's site.
Experience
Sojourner PWA
https://github.com/loomchild/sojourner-webLive version:
https://fosdem.sojourner.rocks
https://flowcon.sojourner.rocks
Written in Vue.js using VueX, Material Design.
Puffin
https://github.com/puffinrocks/puffinThe project's goal is to allow the average, tech-oriented user to run web applications without worrying about a server. The idea is to create an easy-to-host, technology-agnostic private cloud.
While many other tools are looking at containers as a way to run massive applications, Puffin concentrates on lightweight ones, each serving just a handful of people.
Wrote using Docker, Python, and Flask.
Live demo: http://puffin.rocks
Volume-backup
https://github.com/loomchild/volume-backupMulti-regional company Website
https://www.wemaintain.com• UK: https://www.wemaintain.co.uk/
• Singapore: https://www.wemaintain.com.sg/
All the content is managed autonomously by the client via Webflow Editor directly or via CMS. The website has a fully functional blog migrated from an existing blogging platform. The website is integrated with Salesforce CRM and contains custom price-calculation forms.
Tech Blog
BurstLogging
https://github.com/loomchild/burstloggingIt works by temporarily keeping all log records in a buffer. It preserves their chronological order by dropping debug messages that are older than the recently logged message. There is no huge performance penalty because the message is formatted only when it's emitted.
Written in Python.
Reload
https://github.com/loomchild/reloadWritten in Python using the Watchdog library.
Segment
https://github.com/loomchild/segmentThe tool is optimized for performance, both in terms of processing power and memory consumption (it allows streaming processing). It has been used in commercial, open-source (LanguageTool) and scientific applications to process large text corpora, such as Wikipedia archives.
Written in Java.
I have also co-written a scientific paper based on this tool: https://loomchild.net/files/2013/12/Using_SRX_standard_for_sentence_segmentation_in_LanguageTool.pdf
Maligna
https://github.com/loomchild/malignaWritten in Java. Hosted on Maven central, used in commercial and scientific applications.
I have co-authored a scientific paper based on this tool: https://loomchild.net/files/2013/12/A_new_tool_for_the_bilingual_text_aligning_at_the_sentence_level.pdf
Skills
Languages
JavaScript, SQL, CSS, HTML, Java, Python, Regex, Bash, TypeScript, SCSS
Frameworks
Vuetify, Nuxt.js, Django, Flask, Vue SSR, Tailwind CSS, Selenium, Ruby on Rails (RoR)
Libraries/APIs
Vue, Vuex, Node.js, Google Apps, SQLAlchemy
Tools
Git, Vim Text Editor, GitLab, Amazon CloudFront CDN, Slack, Trello, Confluence, Jira, Auth0, Amazon CloudWatch, Amazon EBS
Paradigms
Agile, Kanban, Scrum, Test-driven Development (TDD), DevOps
Platforms
Webflow, Docker, Webflow CMS, Azure, Amazon Web Services (AWS), Debian Linux, Firebase, Linux, MuleSoft, Netlify, Ubuntu Linux, AWS Lambda, Oracle, Amazon EC2
Storage
Cloud Firestore, Elasticsearch, PostgreSQL, MongoDB, Databases, JSON, Google Cloud, Azure Cosmos DB, Amazon DynamoDB, MySQL, NoSQL, Amazon S3 (AWS S3)
Other
Scrum Master, Progressive Web Applications (PWA), Front-end, Web Applications, APIs, Alpine.js, Computer Science, Firebase Cloud Functions, Architecture, FIX Protocol, OAuth, Batch Scripting, Serverless, Segment, PWA, Cloud Architecture, System Architecture Design, Vue 3, Directus
Education
Master's Degree in Computer Science
Adam Mickiewicz University - Poznan, Poland
Exchange Student / Socrates-Erasmus Programme in Computer Science
Heinrich Heine University - Duesseldorf, Germany
Certifications
Certified Scrum Master
Scrum Alliance
Java Programmer (SCJP 6.0) Certificate
Sun / Oracle
How to Work with Toptal
Toptal matches you directly with global industry experts from our network in hours—not weeks or months.
Share your needs
Choose your talent
Start your risk-free talent trial
Top talent is in high demand.
Start hiring