Looks like you have JavaScript disabled. For the full Twine experience, you will need to re-enable it.

I'm Stefan Grzemski, a senior software engineer from Poland with over a decade of hands-on experience building and maintaining web applications in PHP and JavaScript stacks. My background spans e-commerce platforms, a high-traffic educational social network, and custom software projects for European clients. I enjoy owning backend logic, user account flows, database schemas, and the integration points that hold a membership site together. I work well with small remote teams and non-technical stakeholders, thrive in tight iteration cycles, and focus on delivering reliable releases with clear documentation and frequent demos.…I'm Stefan Grzemski, a senior software engineer from Poland with over a decade of hands-on experience building and maintaining web applications in PHP and JavaScript stacks. My background spans e-commerce platforms, a high-traffic educational social network, and custom software projects for European clients. I enjoy owning backend logic, user account flows, database schemas, and the integration points that hold a membership site together. I work well with small remote teams and non-technical stakeholders, thrive in tight iteration cycles, and focus on delivering reliable releases with clear documentation and frequent demos.

Stefan Grzemski

Full Stack Developer, Web Developer, Front-End Developer, +3





I'm Stefan Grzemski, a senior software engineer from Poland with over a decade of hands-on experience building and maintaining web applications in PHP and JavaScript stacks. My background spans e-commerce platforms, a high-traffic educational social network, and custom software projects for European clients. I enjoy owning backend logic, user account flows, database schemas, and the integration points that hold a membership site together. I work well with small remote teams and non-technical stakeholders, thrive in tight iteration cycles, and focus on delivering reliable releases with clear documentation and frequent demos.…I'm Stefan Grzemski, a senior software engineer from Poland with over a decade of hands-on experience building and maintaining web applications in PHP and JavaScript stacks. My background spans e-commerce platforms, a high-traffic educational social network, and custom software projects for European clients. I enjoy owning backend logic, user account flows, database schemas, and the integration points that hold a membership site together. I work well with small remote teams and non-technical stakeholders, thrive in tight iteration cycles, and focus on delivering reliable releases with clear documentation and frequent demos.

Available to hire

I’m Stefan Grzemski, a senior software engineer from Poland with over a decade of hands-on experience building and maintaining web applications in PHP and JavaScript stacks. My background spans e-commerce platforms, a high-traffic educational social network, and custom software projects for European clients. I enjoy owning backend logic, user account flows, database schemas, and the integration points that hold a membership site together.

I work well with small remote teams and non-technical stakeholders, thrive in tight iteration cycles, and focus on delivering reliable releases with clear documentation and frequent demos.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Intermediate

Language

English

Fluent

Work Experience

Senior Software Engineer at code and soda

December 1, 2023 - Present

Led refactor of a Node.js/React application, restructured the backend service layer, replaced ad-hoc caching with a Redis-backed strategy to reduce DB load without stale data, introduced structured error handling and request validation, collaborated with product to define and build a data-visualization module, set up CI/CD with tests and rollback, modernized authentication to a token-based flow, and documented deployment and common failure modes for onboarding.

Full Stack Engineer at TopieT GmbH

March 1, 2020 - September 1, 2023

Built and maintained custom web applications for German clients, delivering a membership portal with tiered access and subscriptions (PHP/MySQL) and integrating a third‑party forum. Improved module performance through targeted SQL indexing, and documented API endpoints and deployment procedures while coordinating with a remote product owner to translate requests into actionable plans.

Software Developer at Brainly

September 1, 2017 - February 1, 2020

Contributed to a large PHP application serving millions of students, overhauled the content submission workflow with server‑side validation and duplicate detection, added monitoring around user registration and login, and participated in on‑call incidents. Collaborated with product managers and QA to define acceptance criteria and ensure quality before deployment.

Software Developer at Silk Software House

September 1, 2014 - August 1, 2017

Built and maintained e‑commerce websites with PHP/MySQL, including an internal order management interface for non‑technical staff, integrated payment gateways and shipping APIs, migrated legacy sites to a modern PHP framework with preserved SEO, and authored reusable components and database migration scripts to speed up new client onboarding.