Daniel Kucal

Taken responsibility for the three following projects:

• ClevAir: HVAC automation and optimization system for commercial buildings
  • Maintained several NestJS-based microservices, two Angular frontends, and AWS infrastructure
  • Developed UI and API for information TV screens with charts showcasing cost and energy savings
  • Implemented and improved integrations with IoT devices (Balena, Emerson, Piscada Graphql, WorldWeatherOnline)
  • Narrowed down performance bottlenecks and optimized them, systematically reducing AWS costs
  • Rewritten legacy Express.js codebases to NestJS, migrated pipelines from BitBucket to GitHub Actions
• RankFor.ai: visibility optimization and benchmarking tool in Large Language Models (LLMs)
  • Set up a properly typed and architected NestJS+React project from vibe-coded source code
  • Secured the application by integrating Authentik and OIDC client for authorization
  • Created a protected proxy supporting Gemini and OpenAI APIs
  • Set up a docker-compose workflow orchestrating frontend, backend and Redis services
• YOLI: led frontend development of YOLI Create Portal
  • Implemented authorization with next-auth, react-query, Axios, and Firestore
  • Developed PDF generating solution for sticker paper using PlayWright
  • Designed application architecture with custom providers, hooks, and reusable components
  • Crafted custom game builders and tables with search and filtering functionalities
  • Helped to shape API and core backend (Python+FastAPI) models, fixed BE Swagger issue
  • Seamlessly integrated AI tools into workflows, boosting the efficiency of app development

Leading innovative maps/plans processing project:

• designed entire architecture using NX monorepo and setup architecture on public cloud using AWS CDK;
• developed frontend seamlessly integrating Leaflet.js into Angular v19 application with custom controls;
• enhanced Leaflet viewer with drawings settings, specifically for color and shape background opacity;
• created CI/CD pipelines from scratch using Github Actions;
• implemented parallel map processing system on AWS, consisting of:
• custom Docker image utilizing sharp for PDF to image conversion running on Step Functions organizing Lambdas;
• generating map tiles for Leaflet simultaneously running Lambda functions;
• applying drawings stored in GeoJSON to PDFs, prepended by coordinates and scale conversion;
• data storage in DynamoDB and file storage on S3 buckets;
• developing real-time bidirectional communication using GraphQL hosted on AWS AppSync;

Developed a base for ChatGPT-like apps exposing most popular AI/ML models (like GPT-4, Gemini, DALL·E, Whisper, Stable Diffusion, 11labs) for text, image and audio generation. This solution consists of few key layers:

• PWA (Angular) - providing a consistent UI across each model type, with local history (RxDB) and special capabilities like audio from video extraction;
• Proxy for external APIs (Bun) - allows on-the-fly file saving to S3 bucket and better handling for special cases, supports SSE (Server-Sent Events) for data streaming;
• Keycloak - for SSO, authorization and user management;
• Signaling Server (Bun's websockets) - matching devices for WebRTC connection for P2P data sharing;
• AWS API Gateway - signing Amazon S3 URLs, storing short-lived data in DynamoDB etc.;

Ask me for a showcase!

[Fixed-term contract]

Hired to develop an AWS Lambda function using node.js for seamless high-volume data integration. The objective was to extract, filter, and parse 2 types of logs stored in Amazon S3 bucket and subsequently forward it to Microsoft Sentinel (Azure Logs Analytics) in chunks. Upon joining, the project encountered a roadblock at the step of fetching/unpacking gzip archives. Successfully identified and resolved the issue, expediting the data integration process ahead of the anticipated timeline. Key accomplishments included:

• Prototyping core parts of the program using bun;
• Establishing local environment with serverless, nodemon, and data population script;
• Applying best practices by utilizing unit tests, SSOT, SRP, and TS interfaces;
• Connecting with AWS Secrets Manager to fetch secret tokens;
• Utilizing organization's existing GitLab pipeline templates;
• Delivering a lightweight solution devoid of 3rd party dependencies in the runtime;
• Flawless deploying to DEV, UAT and PROD environments.

[Fixed-term contract]

Provided technical expertise and set direction in a complex project for a renowned German chemistry corporation. Worked closely with a team of 15-20 professionals, and later also in parallel with a second team in a highly agile environment utilizing Scrum concepts like spikes, PoCs, retros, sprint reviews and code reviews for every single PR. The goal of the project was to migrate use cases of Palantir's Foundry.

• Collaborated with a peer engineer to develop an NX monorepo architecture with Angular microfrontends, node.js backend and shared things, including GraphQL-generated content;
• Implemented authentication using Azure Active Directory (now: Microsoft Entra ID);
• Created a custom, unit tests-covered, reusable UI components library from scratch, leveraging Storybook for presentation;
• Prepared various spikes and proof of concepts in order to pick most suitable solutions;
• Effectively addressed a critical issue in the runtime of production environment of considerable complexity, which had initially baffled even the most experienced engineers due to its unique nature;
• Engineered solutions specific to microfrontends architecture;
• Developed a form fields wrapper with validation and error handling;
• Impressed client's developer team with the quality of the deliverables;
• Implemented easy to use, pre-styled chart components wrapping Highcharts;
• Created and customized data tables utilizing AG Grid Enterprise;
• Solved non-deterministic issue in CI/CD pipeline running on Azure DevOps;
• Converted and adjusted monorepo structure with fundamentals for React/Next.js apps.

[Fixed-term contract]

Led the development of an ERP project for a prominent Swiss transportation company with over 3000 employees and a century-long tradition. Subsequently, made significant contributions to the development of comprehensive system for managing information and advertisement displays located in places like shopping malls and ski resorts. Engaged with a diverse array of technologies, delivering pioneering solutions and implementing robust system management tools.

• Upgraded backend and frontend project dependencies (Next.js, React and NestJS at core);
• Implemented a delegation feature, bolstering system functionality.
• Conducted a series of bug fixes and minor improvements, enhancing overall system stability and user experience;
• Developed an innovative solution to load React builds into an Angular application using web components, extending system versatility;
• Created a one-command setup script that handled tasks such as installing all dependencies (core, symlink, in subdirectories), initializing a database in a Docker container, and creating a .env file with default values depending on the operating system;
• Fixed and improved a bash script for generating booking templates;
• Implemented a slideshow component with integrated Google Web Fonts loader;
• Enhanced PDFs generated through the system;
• Configured E2E tests.

[Fixed-term contract]

Working as a contractor for the Google Admin Tool project, the role was pivotal in accelerating the development process. The position provided an opportunity to contribute expertise and gain insights into the Google Cloud Platform environment, specifically cron scripts, Firestore-based CRUD operations, and integrations with various Google APIs.

• Streamlined project workflow by introducing commands for crucial operations like installing dependencies, and orchestrating both the API and Angular application through singular commands;
• Elevated code quality by integrating eslint and prettier with a git precommit hook, then proceeding to amend tests and setting up BitBucket pipelines for concurrent execution of linting, tests, and builds;
• Transitioned the backend express-based application to TypeScript for enhanced scalability and type safety;
• Achieved better project integration by setting up frontend and backend to leverage shared code from a common directory;
• Designed a parser for email signature templates that accommodate variables and conditional constructs;
• Acquired comprehensive experience with Google APIs, notably Gmail, Drive (Sheets), and Workspace Admin SDK.

In a challenging and responsible role leading the client side of the project, a multitude of tasks were undertaken to ensure the platform's seamless operation and development. Major responsibilities and achievements included:

• Management: Efficiently utilized Jira for ticket management and BitBucket for git flow;
• Code Review: Ensured high code quality standards by diligently overseeing all FE pull requests;
• Mentoring: Acted as a mentor for a Junior Developer, guiding their professional development;
• Tech & Design: Selected the right technologies and designed the application architecture in tandem with the backend team;
• Security & Performance: Identified potential performance bottlenecks and security vulnerabilities ahead of time;
• Development:
  • Crafted a unique solution for resizing images to a specific file size prior to uploading;
  • Built an Odata service & request builder with features like nested expansion, sorting, and searching, all integrated with TypeScript typings;
  • Introduced a base class for rich models with capabilities such as strict initialization, cloning, serialization and hooks for inheritants;
  • Developed diverse input components, from straightforward text inputs to intricate dropdowns and popup grid selectors, adhering to a structured abstract class hierarchy;
  • Designed a signature input feature using canvas, optimized for both desktop and mobile, saving only necessary image data;
  • Augmented Kendo UI components like the Grid, Scheduler, FileUploader, and TabStrip with enhanced functionalities;
  • Launched the implementation of a frontend error logger;
  • Orchestrated real-time app updates using SignalR and strategized a method to fetch only connected users across distributed servers;
  • Implemented a system to detect and alert of unsaved changes made by users, especially when they tried to navigate away or close a session;
  • Integrated the TinyMCE editor, tailoring it with custom menu options and image upload features.

Transitioning to a more advanced freelance role, services were provided on a B2B basis, encompassing both programming and consultation. Key projects and accomplishments included:

• Proposing NestJS framework and implementing features for a German startup in transportation field;
• Developing a GraphQL API using Django and crafting an initial Angular application integrated with the API for warehouse management, integrated with existing systems;
• Designing a configurable Angular-based frontend for a coffee machine distributor;
• Beyond coding tasks, configuring a CI/CD environment utilizing Docker and a personal GitLab Runner instance.

Besides commercial projects, there were notable contributions to various Open Source initiatives:

• tslint - adding ignore pattern for max-line-length rule and creating fix for npm v5;
• DefinitelyTyped - adding type definitions for canvas-size package;
• angular - fixing code example in docs;
• RxDB - coming with polyfill for process.nextTick();
• angular-keycloak - observed critical issue and proposed a solution for it;
• ngx-page-scroll - updated entire library to Angular v20
• angular-starter - update to Angular v4.3, removing no longer needed dependency;
• ngx-bootstrap - making components extensible, proposing "close on outside click" functionality;
• ng-click-outside - proposing and implementing improvements;
• angular-library-starter - improvement of library publishing process, proposing changes in tslint configuration;
• tslint-angular - updating by removing a deprecated rule;
• nativescript-localstorage - adding a polyfill for Storage;
• angular-seed-advanced - describing issues for Ahead of Time compilation;
• nativescript-angular-drawer-template - adding fixes for in-app navigation and builds with webpack;
• apollo-angular - update code example with authorization header;
• docs.nestjs.com - fix e2e testing example with Fastify;
• ng2-select - fixing displaying of items in multiselector;
• ng2-file-upload - adding ability to extend its functionality;

In an independent role, there was a focus on developing a substantial Angular application's business logic with the highest quality. Recognized as the go-to person for specialized tasks, the role entailed being well-informed and readily available for assistance. Key accomplishments included:

• Upgrading the entire application from Angular2 RC.0 to the Final Release, ensuring it remained updated;
• Refactoring and developing a Slack-like chat using web sockets;
• Enhancing the file and image upload systems;
• Developing the open-source ngx-store library;
• Streamlining the authentication system by dividing it into two services based on RxJS Observables, which facilitated seamless user switching without page refreshes;
• Prototyping mobile applications for iOS and Android utilizing Telerik's NativeScript platform, reusing various components like authentication, translations, saving data to localStorage, API integrations together with and app-specific services;
• Optimizing the application's source code for the Ahead of Time Angular's compiler, which improved overall app performance, especially speeding up loading times by over 50%.

Regular responsibilities encompassed:

• Introducing new application features;
• Addressing and fixing bugs;
• Reviewing code from other developers;
• Collaborating with the backend team;
• Identifying security vulnerabilities and memory leaks on both FE and BE.

As a dedicated freelancer, I've polished my skills in TypeScript, Angular, and node.js while further refining my JavaScript expertise. My journey encompassed both personal project development and collaborating on others' ventures. I earned recognition with the Rising Talent badge on Upwork and established myself as an expert developer on both codementor and hackhands, offering priority assistance to those in need.

Employed by a software house in a role of Backend/Magento Developer. Involved in various complex tasks and challenges, notable responsibilities included the creation of numerous modules, 2 open-source examples of which are:

• Magento All Categories
• Magento Advanced Breadcrumbs

A key challenge undertaken was the migration and transformation of a complex Magento product database, requiring extensive planning, coordination, and technical expertise. Additional responsibilities included:

• Increasing system administration skills through work with servers across various Linux distributions;
• Enhancing eCommerce capabilities via the integration of shops with external APIs;
• Contributing to the completion of a project based on Symfony2.

The journey into programming began here, where the foundational skills of HTML and CSS transitioned into more complex development tasks. As the Owner, Developer, and Administrator for over four years, responsibilities encompassed leading and developing a thematic forum for Counter Strike 1.6 game servers. The role demanded a wide range of tasks including customizing game plugins, configuring game servers, and creating comprehensive web applications for a vast player base. Key contributions included:

• Development of an automated shop with integrated micro payments, exploiting SMS Premium and bank transfers provided by Dotpay.pl;
• Design and implementation of a system for collating and displaying players' game statistics;
• Creation of an image upload script, augmenting user interaction capabilities;
• Enhancement of MyBB forum engine plugins for improved user experience;
• Forging strategic partnerships with game server hostings: moje-serwery.pl and pukawka.pl;

This hands-on experience provided a solid base in programming, paving the way for further advancement in the field.