Gniewomir Świechowski

Executive Summary

  • Backend/Full stack engineer
  • ~14 years of commercial experience
    • (Proficient) TypeScript/Node/NestJS
    • (Skilled) TDD/DDD
    • (Comfortable) React/Redux/Saga/Storybook
    • (Rusty) PHP/Symfony
    • (Familiar) Python/Bash - scripting
    • (Familiar) Docker/Terraform/Ansible
    • (Familiar) AWS/Azure/DigitalOcean
  • Focused on frictionless automated testing
  • Adaptable when it comes to tooling, languages, libraries
  • I use IntelliJ IDEs, "AI" IDEs, and rarely Vim—but poorly
  • Currently testing capabilities of modern LLMs

Who am I as a professional

Who am I as a person

Personal projects

OAuth2 Authorization Server

Repository: nestjs-oauth-authorization-server
Architecture/Stack: Layered; DDD-like / Node.js; TypeScript; NestJS; Postgres
Stage: MVP complete, improving logging, hardening & e2e tests
Goals: Owned, fully functional, RFC-compliant and production-ready OAuth 2.0 Authorization Server & Client implementing Authorization Code flow with PKCE for public clients - like SPA and mobile apps. Intended as core for other personal projects.

IT Job Market Scrapper+ETL wt LLM data enrichment & classification

Repository: [private] - available on request, but I do not want to make a working scrapper public
Architecture/Stack: Chain of ultra-light scripts for data extraction & processing / Node.js; JavaScript; TypeScript; Puppeteer
Stage: Actively scraping two of four polish IT job boards, normalizing data to common format. Implementing LLM enrichment Goals: Making informed decisions, testing ability of different LLM's to offer structured outputs

Experience

Technology Summary

Concepts

  • Negative Space Programming
  • Modular Monolith
  • Microservices
  • Domain Driven Design
  • Layered/Hexagonal Architecture
  • CQRS, Events, Queues
  • OOP, FP
  • TDD/BDD
  • SOLID

Languages, Runtimes

  • TypeScript: ~5 years
  • JavaScript: ~13 years
  • Node.js: ~6 years
  • Python: ~1 year
  • PHP: ~14 years
  • Shell: ~4 years

Frameworks, Platforms & APIs

  • NestJS: ~3 years
  • Symfony: ~4.5 years
  • Laravel: ~2 years
  • Django: ~1 year
  • WordPress: ~8 years
  • GraphQL: ~3 years
  • REST: ~10 years
  • SOAP: ~2.5 years
  • Salesforce: ~2 years

DevOps, CI/CD, Cloud & Tooling

  • AWS: ~2 years
  • Azure: ~2 years
  • Digital Ocean: ~4 years
  • Docker: ~5 years
  • Vagrant: ~5 years
  • Terraform: ~2 years
  • Ansible: ~2 years
  • Jenkins: ~2 years
  • Kafka: ~1 year

Databases & ORMs

  • PostgreSQL: ~8 years
  • Redis: ~3 years
  • MySQL: ~6 years
  • Doctrine: ~4.5 years
  • Eloquent ORM: ~2 years
  • TypeORM: ~3 years
  • Sequelize: ~2 years
  • Prisma: ~1 years

Frontend Technologies

  • React, Storybook: ~4 years
  • JSS, Styled Components: ~4 years
  • Redux: ~2 years
  • SASS/LESS: ~7 years
  • Vanilla CSS/HTML: ~14 years

... and others. I mostly stick only to commercial experience, although - few of the numbers include my own projects.

Prior Contracts

SwingDev/Hippo Insurance NYSE: HIPPO, insurance, USA

Software engineer remote, from 07-2023 to 07-2025

Part of Agent Enablement and Underwriting teams.

  • Led a large data migration project aimed at filling the gaps in our lead data in Salesforce, involving fuzzy matching of data from different sources without common keys. The project saved a lot of time for our agents, allowing us to keep this part of the organization pretty lean considering their backlog.
  • Planned and documented redesign of Underwriting Domain to increase the visibility of our decision-making process and speed up the process of introducing new products and markets.
  • Partook in smaller projects aimed at improving the productivity of our sales agents.
  • Microservices
  • TypeScript
  • Node
  • NestJS
  • REST+OpenAPI
  • PostgreSQL
  • GraphQL
  • Salesforce
  • SQS

Point of contact for references: Krystian Koper & Andrew Paulson, Engineering Managers

Speychain ltd startup, marketplace, UK

Software consultant remote, from 06-2023 to 06-2023

Scaffolding of the MVP for a contractee team.

  • Worked with business to define domain & map it to the database and GraphQL API design.
  • Set up CI and toolchain for backend development & testing.

One-month contract. Haven't extended because of a more permanent proposition from SwingDev.

  • TypeScript
  • Node
  • NestJS
  • PostgreSQL
  • GraphQL
  • Prisma
  • Heroku
  • Clerk

Point of contact for references: Martin Richter, CTO

Ownplay Inc. startup, mobile game, USA

Software consultant remote, from 11-2022 to 06-2023

  • Created backoffice APIs, React-based SPA admin panels, and part of analytics for a mobile game, and its web-based prototype
  • Built infrastructure for testing, and convinced the team to adopt the same approach for the rest of the project
  • Coached junior developers

The contract was cut short because the company pivot. In March 2024 I received an offer to jump back on board.

  • TypeScript
  • Node
  • NestJS
  • PostgreSQL
  • REST+OpenAPI
  • React
  • Redux

Point of contact for references: Alexander Ovchinnikov, CTO

Aterian NASDAQ: ATER, e-commerce/logistic/ML company, USA

Backend developer hybrid, from 11-2020 to 11-2022

Greenfield project, layered architecture, CQRS, DDD, TDD.

  • As a team, we built from scratch working multi-tenant affiliate platform on top of the Amazon Attribution program, before appropriate APIs were even available and backoffice for parts of the process that could not be automated
  • Built a BDD-like testing solution allowing for fast writing human-readable integration/E2E tests
  • In addition to backend work, I've set up our frontend architecture, which provided a Stimulus-like experience for our frontend developers, after we decided against React and SPA frontend
  • I performed some light DevOps and security-hardening tasks
  • PHP
  • Symfony
  • PostgreSQL
  • TypeScript
  • Vagrant
  • Jenkins
  • GitHub
  • Ansible
  • Terraform
  • Azure

Point of contact for references: Jakub Włodek, Team Leader

Dogadamycie sp. z o.o. translation company, PL

Full stack developer remote, from 01-2019 to 10-2020

  • Led the process of bringing in-house previously outsourced software
  • Built Docker and GitLab-based CI for the company
  • Offloaded long-running workloads to queue
  • Introduced automated testing
  • Unified seven different customer panels into one project—maintenance and QA were killing us
  • Greatly improved UX of the customer journey and automatic valuation process
  • Integrated multiple payment systems and CAT software
  • PHP
  • Laravel
  • PostgreSQL
  • Redis
  • JavaScript
  • JQuery
  • GitLab
  • Docker

Point of contact for references available on request: Robert Siemiński, CTO

Joymile startup, middleman for used cars, PL

Full stack developer onsite, from 04-2018 to 01-2019

  • I convinced my - now friends - then acquaintances to employ a mostly-PHP and JavaScript developer to do Python. They didn't regret this decision. A month later I was contributing on par with my peers.
  • Moved legacy PHP supporting systems and almost 3 years' worth of data to our main Python-based infrastructure
  • We built a mostly React-based customer journey that provided both great UX and gathered every possible bit of data that could help our sales, which we fed to our CRM and marketing automation

Company dissolved, as we were unable to secure another round of financing.

  • Python
  • Django
  • PostgreSQL
  • Redis
  • Kafka
  • GraphQL
  • JavaScript
  • Node
  • React
  • Redux
  • Docker

Point of contact for references: Wojciech Frycz, CTO

Gremi Media SA publisher of "Rzeczpospolita" and rp.pl, PL

Technical Architect onsite, from 09-2016 to 03-2018

Team Leader onsite, from 04-2016 to 08-2016

Senior Web Developer onsite, from 10-2015 to 03-2016

Business impact

  • Added millions of missing pieces of content—lost after previous CMS migration—back to search engines' index
  • Removed discrepancies in our analytics falsifying traffic reports
  • Improved uptime/availability of our main property from around 97.6% to 99.4%
  • Improved loading times for our customers and their consistency by an order of magnitude
  • Reworked our advertising system to allow new ad formats and better experience for our customers
  • The whole process improved our traffic and unique users numbers by around one third

Technical impact

  • Migrated the company from FTP deployment and SVN to Git and on-premises GitLab for the deployment process
  • Banned FTP access to production. I built and maintained GIT<->SVN bridge for the transition period
  • Understood, fixed our implementation and documented a badly misused and misunderstood caching system
  • Introduced automated testing and proper telemetry
  • Increased template and code reuse by orders of magnitude
  • Replaced an assorted collection of PHP 5.2.17 (version enforced by vendor) scripts augmenting our legacy CMS, by self-built Symfony-inspired light framework enabling us to introduce automated testing and creation of Vagrant-based local environments for developers
  • Replaced template-embedded frontend scripts with a proper build process and React-based components
  • Archeotech
  • PHP
  • Symfony
  • JavaScript
  • Node
  • JQuery
  • React
  • Vagrant
  • GitLab
  • Shell

Point of contact for references available on request: Tomasz Witkowski, Director of IT

Uwazaj.pl startup, a middleman between lawyers and customers, PL

Full stack developer remote, from 05-2015 to 05-2017

  • Took over after the software house failed to deliver both in terms of features and quality and built our product from scratch just in time to meet our investor's roadmap
  • Built a visual "no-code" landing page builder for our marketing with A/B testing capabilities, adapted to manage the whole website by our non-technical staff
  • Integrated content-marketing/sales part with our custom CRM and call center
  • Set up our payment system
  • Supported the project during its lifetime as a sole developer/ops engineer
  • PHP
  • JavaScript
  • JQuery
  • WordPress
  • Gulp
  • Foundation
  • SASS

Point of contact for references available on request: Dariusz Koltko, CEO

Idium AS/Idium Kraków Sp. z o.o website-as-service company, NO/PL

Junior PHP Developer onsite, from 05-2014 to 01-2015

Senior WordPress Consultant onsite, from 01-2014 to 04-2014

  • As a team, we built and maintained a framework allowing for ultra-fast delivery of customized, feature-complete WordPress websites for Scandinavian businesses
  • Built an internal application automating the generation of SEO reports used by our sales team
  • Took part in cleanup and hardening efforts after two separate security incidents
  • PHP
  • WordPress
  • JavaScript
  • Shell

Assorted freelance contracts

Web developer remote, from 01-2011 to 06-2015

Building, adding features, and maintaining various websites, WordPress plugins, and themes.

Occasional migration from Joomla or custom solutions to WordPress.

  • PHP
  • WordPress
  • WooCommerce
  • JavaScript
  • SASS/LESS
  • Gulp/Grunt

Internet media

Journalist, editor, and blogger remote, from 10-2007 to 06-2012

Writing for multiple internet media entities, including o2 sp. z o.o. (currently: Grupa Wirtualna Polska), Antyweb and the Polish edition of PC World Computer about IT-related and unrelated topics.

Working as an editor/managing editor in two big blog networks.