Express.js Experts in Berlin

• Led the end-to-end delivery of enterprise full-stack web applications by driving requirement analysis, solution design, frontend and backend development, database design, API integration, code reviews, team coordination, Agile execution, CI/CD deployments, production support, performance optimization, security implementation, and stakeholder collaboration to deliver scalable, high-quality software solutions.

• Founded an AI-powered scheduling and business-management SaaS for SMBs, owning technology strategy, architecture, product development, UX, billing and go-to-market execution.
• Architected and shipped a multi-tenant platform with REST APIs, RBAC, CRM, billing and notifications, powering the manager dashboard, admin console, booking experience and iOS/Android applications.
• Led and mentored 7 software engineers, 1 DevOps engineer, 1 QA engineer and 1 UX/UI designer, while remaining hands-on across backend, frontend and product delivery.
• Built AI voice and chat agents using Python/FastAPI, OpenAI and Anthropic APIs, RAG, pgvector and tool calling; integrated Twilio, Google Calendar/Meet, Stripe and Firebase.
• Owned production infrastructure and automated delivery across separate environments using Docker, Nginx, GitHub Actions and Grafana; represented the company at accelerators and international startup events.

Selected stack: Python, FastAPI, Node.js, Vue 3, React/Next.js, React Native, PostgreSQL, Redis, Docker

• Designed and implemented a hybrid recommendation system (content-based + collaborative filtering)
• Built end-to-end ML pipelines including data processing, feature engineering, model training, and evaluation
• Developed RAG-based LLM systems using LangChain and vector databases for semantic search and knowledge retrieval
• Established MLOps workflows with MLflow for experiment tracking, versioning, and deployment readiness
• Implemented deep learning models (computer vision & classification) using PyTorch and TensorFlow

• Full automation of the software development process: ticket analysis → AI coding agents → pull request → automated code review → deployment
• Multi-tenant architecture with 82 database models and real-time WebSocket monitoring
• Integration of 40+ AI tools with Claude & GPT
• Tech stack: React, TypeScript, Express.js, PostgreSQL, Redis, BullMQ
• Platform in productive use with paying customers

• Provide the Price Listing Service team with prices for all cars and vans in different markets
• Adapt market-specific requirements such as taxes, government subsidies, campaigns
• Import and synchronize new prices for all new and existing cars and store them in the Redis datastore
• Support our product and on-call duty
• Daily business, development of new features, bug fixing
• Pair programming, code review, mob programming
• Develop POCs for new ideas
• Maintain and extend the backend
• DevOps tasks
• Run Kubernetes updates
• Adjust and further develop Kubernetes resources
• Develop and adapt Helm charts
• Adapt and update ArgoCD
• Maintain, adapt, and improve CI/CD

• Delivered a new notifications platform implementation built from scratch to replace existing and upcoming services
• Collaborating with other teams to integrate more domains

Tech stack:

• Data: Scala 3, Apache Kafka, Python, Airflow, Astronomer
• BE-FE: TypeScript, NestJS, Java, Spring Boot, Vue
• Dev-ops: AWS, PostgreSQL, Docker, GitHub Actions, Kubernetes, Helm, ArgoCD

• Building and scaling cloud infrastructure on GCP to support a SaaS platform for industrial clients
• Designing and implementing a data-driven DevOps pipeline for streamlined deployment and CI/CD workflows
• Collaborating with Data Science team on MLOps workflow to automate integrated retraining

• Industry: B2B
• Headless frontend with AEM integration
• Key challenge: Migrating a PWA application in live operation based on .NET and legacy code; the entire application must be converted to React and Express.js/TypeScript
• Technical frameworks: Tailwind, XML, JavaScript, Caddy, ReactJS, Express.js, REST API, JSON
• Cloudflare CDN
• Caddy server with GitHub CI/CD pipeline

• Developed a SolidJS frontend UI for a spectrometric water analysis system on an ARM-based embedded Linux platform
• Prototyped UI in TypeScript React/Nx with LitElements and MQTT integration
• Built production UI using SolidJS, SUID, i18next, Ajv, MQTT.js, C3.js
• Refined requirements with UX team and water analysis system engineers
• Defined and documented system architecture, MQTT message formats, frontend architecture, and development setup
• Set up frontend system from scratch, implemented domain-oriented type system, UI components, and application state
• Managed MQTT pub/sub services and schema-based message validation in frontend
• Coached two junior frontend developers
• Worked in an agile remote team using JIRA, Git, and Bitbucket

I worked on automating cold outreach.

• Developed a queue architecture to support the parallel execution of large volumes of background tasks.
• Integrated multiple email delivery providers.
• Implemented an LLM-based data enrichment process.

Technologies: TypeScript, React, Node.js, Next.js, Drizzle ORM, PostgreSQL, Next-Auth, JWT, Docker, Kubernetes, AWS, CloudFlare, Traefik, Groq, Jest, Figma

Led backend engineering across core domains (main backend, notifications, medical knowledge base, results processing), owning delivery quality, team growth, and engineering standards.

Signature Outcomes

Shipped a flexible, no-code membership platform (pricing, packages, duration), enabling commercial changes without engineering involvement and keeping membership tiers coherent over time.

Built a high-impact backend team through mentorship, coaching engineers into independent contributors and establishing onboarding documentation that enabled fast ramp-up.

Scaled the team from 2 → 5 engineers while maintaining delivery cadence and code quality; owned hiring pipelines and onboarding.

Partnered closely with Product during design to assess feasibility, sequence work, and make pragmatic trade-offs between speed, tech debt, and long-term maintainability.

Institutionalized testing and simplicity as defaults, enforcing high test coverage and a “simple-first” architecture approach.

Tech & Practices

Stack: Node.js (TypeScript), Express, PostgreSQL; microservices (Node & Go); event-driven async jobs.

Practices: Testing as a release gate, lightweight design reviews, iterative delivery, documentation-driven onboarding.

Compliance & Security: Led implementation of Privacy Officer recommendations (GDPR and German healthcare regulations).

• Developing an AI-enabled platform that summarizes YouTube channels into daily digests with article and podcast formats.
• Built scalable backend in Node.js integrating OpenAI Whisper for transcription and GPT for summarization.
• Implemented frontend in React with TypeScript, ensuring responsive design and accessibility.
• Set up automated deployment pipelines and CI/CD with Docker & GitHub Actions.

• Backend & API architecture: Independently architected a scalable Node.js backend and RESTful API to handle a high volume of transactions, ensuring robust data management for users, restaurants, and administrators.
• Microservices & infrastructure: Engineered a sophisticated database architecture using PostgreSQL with geographic query optimization. Designed and deployed a robust infrastructure with three separate microservice servers and a database server.
• Performance & scalability: Implemented Redis caching and performed SQL query optimization to improve application performance and reduce load on the database, enhancing responsiveness for real-time services.
• Security & authentication: Integrated secure payment processing via Razorpay and implemented robust middleware for JWT authentication to ensure secure transactions and data integrity.
• CI/CD & deployment: Established a robust CI/CD pipeline using Docker and GitHub Actions for automated and reliable deployment, showcasing fluency in modern DevOps practices.