Ilya Kremer, Full-stack Web Developer

A close portrait of me looking straight into the camera. In the background are hills partially covered with forest. I’m wearing a light-gray melton jacket, a colorful scarf, and thick-frame black glasses.

I’m a professional web developer with extensive and diverse experience permanently based in Berlin, Germany.

I made my first money in software engineering by teaching parallel programming (mostly Fortran with MPI and OpenMP) to students from other cohorts and programmes.

Over my career, which spans 15 years, I’ve worked with diverse technologies, from Java EE, Freemarker and jQuery to Next.js, Zustand and Playwright, constantly evolving with the industry.

Today, my most-used technologies include React.js, Next.js, Redux Toolkit, Zustand, Playwright, MUI, shadcn/ui, Tailwind CSS, turbo, and more.

My main focus and guiding principle is to maintain high code quality despite the extensive use of AI assistants (my personal favorite is Junie). I believe this not only ensures readability and maintainability but also helps prevent performance issues, reduces bugs, and ultimately improves the overall product quality.

Experience

info.link logo

Front-end Lead Developer

Apr 2025 Sep 2025
6 months
Berlin

Working on the main platform (v1) where clients configure and build their info.link pages:

  • Enhanced some modules functionality (e.g., allowed opening links in full-screen dialogs).
  • Implemented new features such as entity removal.
  • Made minor design improvements.

Working on the main platform (v2):

  • Rewrote the entire application from scratch, improving its structure, functionality, and maintainability.
  • Enhanced app design, including the customer-facing pages.
  • Improved search functionality.
  • Implemented support for multiple languages and regions.
  • Developed a robust versioning system using a Draft/Published/History model.
  • Reworked the /new page for improved usability, structure and maintainability (easier to configure from the admin dashboard/Payload CMS).
  • Reworked the settings page, so it reduced the need to contact support.
  • Set up GitHub Actions for Playwright tests.
  • As lead developer, proactively addressed minor design issues, visual inconsistencies, and responsiveness across the UI to deliver a more cohesive and polished user experience compared to the previous platform version.

Working on the the info.link public website:

  • Applied best practices for SEO and geo-targeting, resulting in significant performance improvements confirmed by internal analytics, Peec.ai audits, and hands-on testing.
  • Polished and dynamic sitemap.xml with priority weights.
  • Optimized meta tags for each page.
Next.jsReact.jsPayload CMSshadcn/uiTailwind CSSZustandturbo

bonify logo

Front-end Developer

May 2024 Sep 2025
1 year, 5 months
Berlin

Working on my.bonify.de main web app, as well as on SCHUFA Basisscore, Finanzmanager, KYC and web-marketing (bonify.de/* pages) web apps, and also on SSO pages:

  • Worked on the registration flow redesign.
  • Led the process of creating the bank transactions consent/bank account deletion pages and the related functionality.
  • Contributed complex changes to the Dashboard, Profile, FinFitness and other pages.
  • Actively suggested improvements to the proposed design.
  • Actively proposed and carried out the tasks related to the design flaws, wording, UX issues (accessibility, bundle size, performance and stability).
  • Promoted better coding practices among the teammates.
  • Contributed to Android and iOS apps.
  • Worked on the infrastructure improvements: SonarQube integrations and various upgrades.
  • Worked on ConvertFlow and Landingi integrations.
React.jsRedux ToolkitViteVitestNext.jsstyled-componentsTailwind CSSReact NativeOAuth 2.0Jenkins

Delivery Hero logo

Front-end Developer (Pandora)

Aug 2022 Apr 2023
9 months
Berlin

Working on Foodora, Foodpanda, Mjam, Yemeksepeti websites:

  • Worked on Planned Order functionality.
  • Worked on Cart page functionality:
    • Rider Tips component;
    • Cutlery widget, and many more.
  • Worked on Checkout page functionality:
  • Added powerful e2e tests (Cypress) for Cart and Checkout pages.

During my tenure at DH I proactively referred four engineers from my network who were hired and successfully passed probation.

React.jsReduxSassCypress

Delivery Hero logo

Full-stack Developer (Logistics)

Mar 2020 Jul 2022
2 years, 5 months
Berlin

Working on back-office applications:

  • Heavily contributed in a newly created web app for configuring rules for automatic issues resolution (rider issues, restaurant issues, etc.).
  • Contributed to useHurrier — a huge web app for manual issues processing.
  • Participated in rewriting useHurrier with a new stack and significant UI/UX improvements:
    • Google Maps functionality;
    • Grid virtualization, and many-many more.
React.jsRedux-SagaSWRstyled-componentsMaterial UIArmorCypress

Avito logo

Full-stack Developer

Apr 2016 Feb 2020
3 years, 11 months
Moscow

Avito is the biggest classified ads website and app in Russia launched in 2007. There are typically over 100M of active ads at the moment and hence billions of hits per day. It's estimated to be in the Top-10 visited websites in the country.

Working on www.avito.ru and m.avito.ru websites (implementing the given functionality on both desktop and mobile):

  • IM application features:
    • Sending a CV as a message;
    • Searching through possible attachments.
  • Safe deal & shipping service features:
    • Created a widget for ordering and implemented all corresponding IM functionality (system messages) from scratch.
    • Created corresponding back-office tools from scratch (claims resolution).
    • Created a customer service for making failed delivery claims from scratch (customer-facing).
    • Worked on the related functionality on the main, search and ad (item) pages.

Published a post about visiting the FullStack 2017 conference held in London on a company’s behalf to promote corporate culture.

React.jsReduxPHPTwigCSS Modulesstyled-componentsGolangAvito UI

IPONWEB logo

Full-stack Developer

Mar 2014 Apr 2016
2 years, 2 months
Moscow
  • Worked on BidSwitch UI (my.bidswitch.net interface for customers).
  • Worked on the u-Workflow project.
AngularJS (1.*)Bootstrap 2LessDjangoGrunt

PROGNOZ logo

Full-stack Developer
@ PROGNOZ

Aug 2012 Mar 2014
1 year, 8 months
Moscow

Contributed to large-scale greenfield projects from initial architecture through to production launch:

jQueryRaphaëlHighchartsPHPYiiOracle

AT Consulting logo

Web Developer
@ AT Consulting

Dec 2011 Aug 2012
9 months
Moscow
  • Worked on multi-step forms for https://gosuslugi.ru.
  • Developed helpful FreeMarker macros (basically a library for creating forms).
  • Administrated the server running the main app.
jQueryFreemarkerJavaOpenSUSEOracle 11gApacheDSTomcatWSO2ESB

Own Projects

Ilya Kremer Stories logo

Maintainer

Dec 2025 present

My personal, wedding-focused photography website — a revival of a project I first created in 2010–2011 using PHP, MySQL, jQuery, and its plugins — prettyPhoto (Lightbox clone) and Lazy Load.

React.jsNext.jsnext-intlTailwind CSSturboreposhadcn/uiNeon PostgreSQLVercel Blobnuqszod

Naturalizatio logo

Maintainer

Jan 2025 present

A pet project of mine that went public. Here one can prepare for several naturalization exams and also use — in my opinion — the most well-designed, precise and detailed German salary calculator ever made.

React.jsNext.jsnext-intlMaterial UIRedux ToolkitNeon PostgreSQLUpstash RedisVercel BlobnuqszodreCAPTCHA

Maintainer

Oct 2022 present

CLI utility for operating Elgato Key Lights. Such a powerful tool for a less than 10 kB dist file!

ZshBashMakefilecurl

Naeplagiat logo

Founder & Maintainer
@ Naeplagiat

Jan 2014 Jun 2016

A plagiarism detection hack service for students (probably the bad ones).

Students could pay here for an artificial increase of a document’s uniqueness rate in order to bypass the plagiarism detection system (which was not working fairly and many universities were abusing it).

PHPYiiMySQLjQueryGulp

Maintainer

Jun 2013 Jun 2017

Dropdown plugin for jQuery supporting dozens of features.

Back in time my former manager from AT Consulting offered me some freelance for a Russian Post online project. I created this plugin as a result of working on a web form and started to maintain it separately.

One day I saw it in use on the very famous mass media website and was super happy about that.

jQuery (core)

Education

PFUR (RUDN) logo

Sep 2007 Jun 2014
Moscow

Master’s degree plus a preparation course.

Computer science:

  • C/C++, including Inter-Process Communication (Linux).
  • Fortran: parallel programming (both MPI & OpenMP).
  • Java (desktop apps only).
  • POSIX Shell, GNU, Virtualization.

Math:

  • Understanding why √2 is irrational.
  • Understanding why the area of a circle is πr².
  • And even more than that!