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serdjukow.eu

Sergej Serdjukow, Software Engineer, Berlin, Germany

Software that keeps working when things fail.

Scalable web applications and event-driven systems on AWS — built for retries, duplicates and traffic spikes.

  • Next.js
  • TypeScript
  • AWS
  • Serverless
  • AI
Explore engineering storiesGet in touch

Decorative animation: a simulated event-driven pipeline. Events flow from producers through an API and a queue to a pool of six workers and into a store; failed events are retried with backoff and moved to a dead-letter queue after three attempts.

Case studies

Engineering stories

Problems from production systems, the trade-offs behind the solution, and what changed.

Projects

Selected projects

Production systems from my work at Formilo and ComonGames, and a few tools I built on my own.

  • Formilo, 2025–today, Main developer

    Async outreach platform

    Production platform on AWS Amplify Gen 2. It discovers companies, scrapes and AI-scores their websites, generates personalised emails and runs scheduled campaigns with live status.

    • ~60 Lambda functions and 25 custom GraphQL mutations over 21 models
    • SQS worker pipeline with DLQ and reconciliation, processing jobs of several thousand websites with capped concurrency
    • One EventBridge schedule per email, created idempotently, with a 30-minute reconciler
    • Webhook-driven external jobs with a polling fallback
    • Next.js 15
    • React 19
    • MUI
    • TanStack Query
    • AppSync
    • DynamoDB
    • Lambda
    • SQS
    • EventBridge Scheduler
    • S3
    • Cognito
    Read the engineering stories

  • Formilo · team project, 2025–2026, Lead developer

    Coaching Planner CRM

    Manages coaches, coachees, absences and holidays, appointment scheduling and capacity, sends timesheets and invoices by email and exports to PDF and Excel.

    • Custom “day-first” scheduling engine: one appointment per day, at most 3 consecutive days, strict 1:1 per coach, holidays and absences respected
    • Engine covered by ~50 Vitest suites, including golden, stress and capacity tests
    • Idempotent batch-creation Lambda with a DynamoDB-based distributed lock (TransactWrite + TTL)
    • R&D extension: LLM-based scheduling as an async job (DynamoDB stream → Lambda) with OpenAI/DeepSeek providers and deterministic validation of the AI output
    • React 19
    • Vite
    • TypeScript
    • MUI
    • TanStack Query/Table
    • FullCalendar
    • Amplify Gen 2
    • Cognito
    • AppSync
    • DynamoDB
    • S3
    • Lambda

  • Client project via Formilo, 2026, Solo full-stack

    Contract-amendment workflow platform

    Release candidate

    Replaces a legacy PDF form for recording and routing contract changes at a German kitchen retailer.

    • Role-based workflow (sales, back office, admin) with hand-backs, substitutions and a full change history
    • Server-side PDF generation with Playwright: internal and customer versions, with versioning
    • Postgres-backed email outbox with retry workers and archive integration
    • Security hardening (CSRF, rate limiting, encrypted SMTP credentials), 200+ server test files, CI, Docker Compose + Caddy
    • Node.js 24
    • TypeScript
    • Express 5
    • Prisma 7
    • PostgreSQL
    • React 19
    • Vite
    • Tailwind v4
    • TanStack Query
    • Playwright
    • Docker

  • ComonGames, 2024–2026, Frontend

    Sacralium — game landing & shop

    Marketing and registration landing page for the browser MMORPG Sacralium, with sign-up and login against the game’s forum API, plus a static in-game shop with payment status pages and legal pages.

    • Containerized deployment via GitLab CI
    • HTML
    • SCSS
    • JavaScript
    • Docker
    • GitLab CI
    sacralium.game (opens in a new tab)

  • Personal project, 2024–2025

    Konnektor Kompass

    Free, non-commercial trainer for German connectors and prepositions: verbs, nouns and adjectives with their prepositions.

    • Collects no personal data
    • React
    • Chakra UI
    • TanStack Query
    • Framer Motion
    konnektor-kompass.vercel.app (opens in a new tab)

  • Personal project, 2026

    Medicina Legale quiz

    Exam trainer for Italian forensic-medicine questions with Russian translations, progress tracking and a review of past mistakes.

    • Versioned localStorage progress with migrations
    • Parser that turns source text into question JSON
    • React
    • Chakra UI
    med-quiz-tau.vercel.app (opens in a new tab)
Sergej Serdjukow

About

Hi, I’m Sergej.

I studied Information Systems and Information Technologies in Moscow (B.Sc., 2000–2005). In Berlin I retrained as a Fachinformatiker for application development at Forum Berufsbildung (2019–2021) and as a web developer at Tel-Ran (2021).

From 2021 to 2024 I was a frontend developer at ComonGames, building component-based interfaces with React and Next.js. Since February 2025 I have been a software developer at Formilo, working full-stack on serverless AWS (Amplify Gen 2, AppSync, Lambda, DynamoDB) and integrating AI features.

I write about asynchronous systems on LinkedIn. I speak German (C1) and Russian (native), live in Berlin and am open to remote work.

Away from the keyboard: stand-up paddling, extreme cycling routes and my guitar.

Get in touchLinkedIn (opens in a new tab)

Experience

Where I have worked

From frontend work on websites and games to full-stack systems on serverless AWS.

Berlin · open to remote

  1. – today

    Software Developer, Formilo

  2. –

    Frontend Developer, ComonGames

  3. –

    Frontend Developer, Adler Technologie

  4. –

    Frontend Developer, Forum Berufsbildung

Show details

  • Formilo, Software Developer, Berlin

    • Performant, scalable web applications with React, Next.js and TypeScript, backed by serverless AWS infrastructure.
    • Modular frontend architectures, REST API integration and responsive UI components with MUI, shadcn/ui and Chakra UI.
    • Architecture decisions, feature planning and deployment, including AI-powered features and automated workflows.
    • AWS
    • React
    • Next.js
    • TypeScript
    • Zustand
    • TanStack Query

  • ComonGames, Frontend Developer, Berlin

    • Modern frontend solutions and component-based user interfaces.
    • Close collaboration with backend and DevOps teams in agile processes.
    • Implementation and optimization of UI/UX.
    • React
    • Next.js
    • TypeScript
    • REST API
    • Material UI
    • Firebase
    • Git
    • Figma
    • WordPress

  • Adler Technologie, Frontend Developer, Berlin

    • Development and optimization of web applications, system integrations and frontend solutions.
    • Architecture meetings, code reviews and refactoring.
    • React
    • JavaScript
    • Node.js
    • Redux
    • HTML5
    • SASS
    • MySQL
    • Git

  • Forum Berufsbildung, Frontend Developer, Berlin

    • Analysis and optimization of existing websites, plus frontend and CMS tasks.
    • Technical research for shop and platform solutions.
    • JavaScript
    • WordPress
    • REST API
    • HTML5
    • CSS3
    • Figma
    • Git

Education

  • –

    Web Developer

    Tel-Ran Educational Center

  • –

    IT Specialist for Application Development (Fachinformatiker Anwendungsentwicklung)

    Forum Berufsbildung e.V.

  • –

    B.Sc. Information Systems and Information Technologies

    State University of Information Technologies, Radio Engineering and Electronics, Moscow

Languages

German
C1
Russian
Native

Writing

Articles

Notes from building event-driven systems on AWS.

All articles on LinkedIn (opens LinkedIn in a new tab)

Contact

Let's build something reliable.

A system that has to stay up under real traffic, an idea for an article or a role to talk about: I am happy to hear from you.

Write an email
E-Mail
sergej@serdjukow.eu
LinkedIn
linkedin.com/in/sergej-serdjukow-a55bb0b4 (opens in a new tab)

Built with Next.js 16, Tailwind CSS and CanvasHosted on VercelGitHub (opens in a new tab)Built