Jest Experts in Munich

Alexandru G.

Head of Cloud Infrastructure

Last position:

Principal Cloud DevOps Architect at BP

In my role as Senior Cloud DevOps Architect for BP, an oil and gas company, I had the mission to migrate the Electric Vehicle Charging platform of the EV Division from on-premises and Azure to AWS cloud, resulting in a hybrid multi-cloud, multi-tenant SaaS solution.

Deployment with Kubernetes for the application layer meant provisioning Kubernetes clusters managed by EKS and AKS, with a focus on integrating them into a multi-tenant environment. This integration was achieved by using Kubernetes namespaces and access controls to ensure data isolation and privacy enforcement.

In the database layer, we chose an RDS instance with PostgreSQL to support the backend infrastructure of our applications. Tenants shared the same RDS instance, but each had a dedicated schema.

To ingest near real-time data from physical charge points (CPOs), as IoT devices, via the OCPI protocol, we ran into significant delays with batch processing. As a result, we built a real-time streaming data pipeline using Apache Kafka, while prioritizing an event-driven architecture.

Led collaboration across multiple internal teams, external vendors, cloud providers, and on-site partners to integrate over five systems into a unified solution.

Achievements:

Successfully designed and implemented hybrid multi-cloud solutions, integrating multiple cloud platforms (AWS, Azure) with on-premises infrastructure, using Site-to-Site VPNs, Firewalls, and Load Balancing.
Led the migration of on-premises infrastructure to multi-cloud, multi-tenant infrastructure, resulting in 30% faster processing times.
Migrated workloads from VMware and Hyper-V environments to cloud-based VMs, leveraging cloud-native services to optimize performance, cost efficiency, and scalability.
Designed a multi-tenant Kubernetes platform leveraging the Kubernetes ecosystem, using Karpenter for dynamic EC2 node provisioning, KEDA for event-driven pod autoscaling (e.g., Kafka message lag), and Rancher for centralized monitoring of multiple clusters (EKS, AKS, or on-prem K8s), replacing Microsoft-centric Azure Arc management service.
Designed and implemented Python-based FastAPI microservices as part of the EV core-backend on AWS EKS application layer, powering data ingestion and customer analytics pipelines.
Developed asynchronous, event-driven APIs (Python-FastAPI) for real-time integration with CPOs, supporting OCPI 2.3 and OICP protocols.
Designed and implemented a secure, production-grade Azure Databricks platform using Terraform, ensuring scalability and cost efficiency.
Migrated on-premises ERP to a hybrid Dynamics 365 architecture with ERP hosted locally and CRM running in Azure, integrated via Azure Arc.
Automated CI/CD pipelines for Databricks notebooks and jobs using GitHub Actions & Databricks CLI, reducing deployment time. Reduced infrastructure provisioning time by 70% by automating cloud resource deployment with GitOps.
Ensured compliance with internal audit and data governance standards (GDPR) through OAuth2/OIDC-based authentication and fine-grained role-based access controls.
Developed a Zero Trust security model, enforcing least-privilege access and microsegmentation, enhancing security posture and compliance with GDPR and NIST.
Built interactive analytics dashboards in Amazon QuickSight, integrating data from S3 and Redshift to deliver real-time business insights and visualizations with embedded access for multi-tenant users.
Led cloud security assessments and full-lifecycle cybersecurity integration during M&A, covering AWS, Azure, IAM (Entra ID), and data protection, while aligning security posture with NIST, ISO 27001, and GDPR across hybrid and cloud-native environments.
Reduced cloud costs by 64% for a client's dev environment by implementing automated start/stop schedules for EC2 and RDS instances via AWS CDK with EventBridge Scheduler or AWS Systems Manager.

Tech stack:

Infrastructure as Code: Terraform, AWS CDK, Ansible.
Containers: Kubernetes on EKS, AKS, Docker.
Streaming Data Processing: Kafka to Confluent Cloud, after AWS MSK.
Frontend: TypeScript, React, NextJS, Hooks, Styled Components.
Backend: Python with FastAPI, also Node.js with NestJS.
Database: Aurora on PostgreSQL with TypeORM, RDS on SQL Server, Azure Databricks full setup and administration, ETL Pipelines.
CI/CD and GitOps: GitHub Actions, Azure DevOps, ArgoCD.
Monitoring and Observability: Prometheus and Grafana.
Virtualization: Hyper-V, VMware Cloud on AWS, Azure Migrate.
ERP Systems: Odoo, Microsoft Dynamics 365 Business Central on Azure, integrated with Azure Arc.
Networking: Site-to-Site VPNs, AWS Direct Connect, Azure ExpressRoute, Firewalls (AWS Network Firewall, Azure Firewall).
Security: IAM, NIST Framework, Zero Trust Security, AWS WAF, AWS Shield, GuardDuty.

Luigi C.

Full Stack & AI Engineer

Last position:

Senior Full Stack Developer at Almuc Advertising GmbH

Applied modern JavaScript features, including ES6+ syntax, destructuring, modules, array methods, and asynchronous programming, to develop efficient and readable frontend code.
Implemented frontend integration patterns for PHP and Laravel backend services, connecting React interfaces to REST APIs and handling structured JSON data.
Developed interactive, functional component-based frontend applications using React Hooks, JavaScript, and TypeScript, alongside backend applications and RESTful APIs using Python, Django, Flask, and FastAPI, focusing on reusable components, modular architecture, maintainability, and efficient data processing.
Maintained a dynamic portfolio platform using PHP, Laravel, Livewire, and MySQL, implementing end-to-end functionality across frontend interfaces, backend services, and database operations.
Validated server-side request handling, routing, middleware, and form validation using Laravel features to support reliable application workflows and consistent data processing.
Designed and managed relational database structures using MySQL and Laravel Eloquent ORM, implementing data models, relationships, database migrations, and efficient queries for content management.
AI-powered applications integrating Large Language Models (LLMs) through external APIs and locally hosted models, exploring practical use cases for conversational AI, intelligent automation, and AI-assisted workflows.
Built local AI applications and developer tools for running, configuring, and interacting with locally hosted language models, gaining experience with local inference, model integration, and privacy-conscious AI workflows.
Explored Retrieval-Augmented Generation (RAG) approaches to combine language models with external knowledge sources, enabling context-aware responses based on relevant application data and retrieved information.
Integrated AI services with backend APIs and application components, developing reusable modules for model communication, response processing, error handling, and data exchange.

Michael T.

Senior Software Engineer — Backend Systems | Data Engineering | Enterprise Integration | Cloud Applications

Last position:

Senior Freelance Software Engineer — Enterprise Software & Data Projects

Delivered backend systems, data processing solutions, and software integrations for enterprise business applications.
Designed and implemented API-based services connecting internal platforms with external systems.
Built automated processing workflows to handle large-scale structured business data.
Improved application performance by 30–50% through database optimization, caching strategies, and backend refactoring.
Reduced manual operational effort by 40–60% by automating repetitive workflows.
Supported production environments through troubleshooting, monitoring improvements, and continuous optimization.
Authored technical documentation and led knowledge-transfer sessions to support long-term maintainability.

Umut T.

Senior Product Engineer | Frontend, Full-Stack & Design | React & React Native

Last position:

App Engineer at Tonies SE

Worked as an App Engineer as part of the IoT Control team in a React Native Stack.

Implementing new Components based on the Tonies Design System.
Improving, extending and maintaining Tonies Design System
Adding new features like Volume and Playback Control of the Tonies
Fixed connection issues via bluetooth and wifi
Removing technical debt and polishing for an upcoming big software and hardware release
Improving accessibility by optimizing screens and components for usage via screen readers.
Wrote lots of automated tests to ensure app quality is always stellar.
Weekly app releases in a high volume workload environment

Results & Impact:

Improved app stability and connection reliability ahead of a major software and hardware release
Raised overall app quality through a significantly broader automated test suite, catching regressions before they reached users
Made the app usable with screen readers, improving accessibility for a wider audience
Sustained a weekly release rhythm in a high-volume production environment without quality regressions

Technologies: react-native, expo, typescript, react-19, react-compiler, react-navigation, zustand, @tanstack/react-query, i18next, figma, app-store, play-store, sentry, bitrise, config-cat, poeditor

Piotr K.

Senior Software Engineer

Last position:

Senior Software Engineer at On

Built middleware service integrating EDI providers and marketplace partners with Microsoft Dynamics 365 to receive sales orders and communicate shipments, invoices, inventory, and price catalogues
Utilized a mixture of REST APIs and event-driven data processing pipelines

Matthias V.

Senior Frontend Developer & Architect

Last position:

Senior Frontend Developer / Technical Web Architect – Consent Management

Project for a leading German email and cloud service provider: As Senior Frontend Developer and Technical Web Architect, I developed an international, multi-tenant white-label consent management layer for multiple brands.

Main tasks:

Architecture and implementation with Vue 3, TypeScript, and Vite
Development of automated tests with Vitest and Playwright
Creation of brand-specific CMP configurations, CSS themes, i18n structures, and vendor settings
Implementation of playout and initialization logic as well as backend integration
Technical decision support, project, and code documentation

Impact: Replacement of external CMP solutions with a reusable and long-term maintainable in-house foundation for several international brands and rollouts.

Technologies: Vue 3, TypeScript, Vite, Vitest, Playwright, IAB TCF, Google Additional Consent, i18n, Git, CI/CD.

David D.

Senior Angular Engineer

Grünwald

Last position:

Senior Angular Engineer at HUK-Coburg

Technologies: TypeScript, JavaScript, Java, HTML, SCSS, JSON, REST, Angular, Nx, NgRx, RxJs, Git, Spring, TFS, Jenkins, Jest, Cypress, UI/UX-Design, Figma, Storybook, Domain-Driven Design (DDD), Micro Frontend, Clean Code, Arc42, Agile, Scrum, Jira, Confluence
Technical conception and further development of a modern Angular web application as part of the portal migration
Built a modular frontend architecture with Nx and clear separation of domain and technical layers (Clean Architecture)
Introduced and implemented Domain-Driven Design in the frontend context, including layer model and linting rules for code organization
Developed reusable UI components and features using Angular, NgRx and RxJS
Integrated the application with backend services via REST APIs
Ensured high code quality through structured code reviews, testing with Jest and Cypress and introduction of guidelines
Performed regular upgrades to new Angular versions to ensure long-term maintainability
Collaborated closely with internal developers, product owners and stakeholders for requirements analysis and solution finding
Supported the team through active knowledge transfer, review coaching and technical decision making
Established a modular architecture with Nx & DDD as the technical foundation for future development
Significantly improved test coverage through systematic introduction of Cypress and Jest tests
Facilitated intensive collaboration with internal developers to build DDD structures and testing strategies
Delivered a modernized UI focusing on clarity, usability and modern web technologies, achieving high acceptance by over 4,000 field staff
Enabled parallel operation of the new Angular portal with the existing .NET system for phased migration of the sales process

Srinivasu K.

Fullstack Developer

Last position:

Atruvia

Project: Tax Exemption Order Application

The client has an existing application for creating and maintaining tax exemption orders for end customers; design and implementation of a comparable application for internal employees.

Design and implementation of microservices and the UI for the business area "tax exemption orders" using Domain Driven Design as well as Spring Boot and Angular.
Implementation of reactive, non-reactive, and asynchronous APIs (Spring REST, WebFlux, GraphQL).
Development of the Angular application, including state management using Signals, RxJS Observables, and subscriptions.
Securing the API and the application using OAuth2, JWT, and OpenID Connect.
Configuration and setup of CI/CD pipelines with Jenkins.
Collaboration with cross-functional teams and conducting code reviews.

Environment: Java, Spring Boot, Angular 18 & 19 (standalone, signals), RxJs, Bootstrap CSS, Vitesting, OpenShift, Istio, microservices, Kafka, Dynatrace, Jenkins, GitLab, Graylog, Sonar, Oauth2, OracleDB

Celso K.

SAP Commerce Cloud FullStack Developer

Ottobrunn

Last position:

SAP Commerce Cloud FullStack Developer at Spar

Implementation of a GitLab CI/CD pipeline based on SAP Commerce Cloud 2211
Development of a new B2C shop with Vue, Node and TypeScript to ensure scalability, extensibility and performance optimization
Integration of Microsoft Azure Event Grid with SAP Hybris
Implementation of BDD with Cucumber using Gherkin syntax to promote collaboration between development and business teams
Support and customization of a Spartacus shop
Technologies/Languages: Java, REST, OData, Behavior Driven Development (BDD), Cucumber, Node, Vue, TypeScript, Spartacus, GitLab CI/CD, Gradle, Maven, Ant, SonarQube

Roxana G.

Freelance Senior Frontend Developer

Last position:

Freelance Senior Frontend Developer at RHI Magnesita

Designed and developed a high-performance internal resource management platform using React and TypeScript, optimizing dynamic data rendering and state management.
Built a React Native application to support mobile access to internal tools, enabling on-the-go project tracking for field teams.
Developed custom 2D canvas-based visualizations using Pixi.js to simulate material flows and refractory layer behaviors.
Integrated Pixi.js with React components for interactive diagrams and real-time UI updates.
Developed interactive 3D visualizations using React.js for displaying refractory product layouts and simulations, supporting engineering and sales teams with dynamic product previews.
Integrated Three.js within the React ecosystem to allow manipulation of 3D models in real-time via browser, enhancing user engagement and field configurability.
Integrated a headless CMS to enable dynamic content updates by non-technical users, reducing content deployment time by 40%.
Led AWS CloudFront optimization initiatives, improving portal load speeds by 30% globally.
Actively collaborated with cross-functional Agile teams and product owners to deliver prioritized features with a fast feedback loop.
Key Technologies: React.js, React Native, Three.js, TypeScript, Contentful CMS, AWS S3/Lambda/CloudFront, Cypress, Agile Scrum

Matthias L.

Typescript Fullstack Engineer

Last position:

Typescript Fullstack Engineer at Card Complete / Bank Austria

Designed and developed the "Credit Risk Engine" using Camunda, Node.js and Typescript
Greenfield project for credit card credit assessment for existing and new customers, including EBA KPIs, SCHUFA and CRIF scorings
Built and modeled workflows (BPMN) and decision logic (DMN) with Camunda Modeler in close collaboration with stakeholders
Implemented service tasks, user tasks and jobs with Nest.js, Node.js and Typescript, including exception handling
Backend-for-Frontend (BFF), frontend with React, Tailwind and Ant Design UI library
CI/CD with GitLab, Kubernetes/Rancher

György K.

Senior Software Developer, Delivery Unit Software Design & Development

Last position:

Senior Fullstack Developer at Rockstardevelopers GmbH

Development of a test system
Establishment of the architecture using Scala/Java for the backend and Swing for the frontend
Setup of CI/CD pipelines with Jenkins for continuous integration, including automated builds
Participation in the Scrum team, including daily stand-ups, sprint planning, and retrospectives
Technology environment: Scala, Swing, EJB, JPA, Scrum, PostgreSQL, Mercurial

Andreas K.

Senior Developer

Last position:

Senior Developer at ioki GmbH, a Deutsche Bahn AG company

Fullstack development based on Next.js and TypeScript
Development and optimization of geospatial database queries for PostgreSQL/PostGIS
Visualization of geospatial data using Mapbox
Design and execution of load tests and performance optimizations
Code reviews and documentation tasks
Technologies: JavaScript, TypeScript, Next.js, React, Zod, tRPC, Storybooks, PostgreSQL/PostGIS, MicroORM, Knex, Material UI, Mapbox, BullMQ, Jest, Playwright, Artillery.io, K6, Sentry, Figma, GitLab, Grafana, GTFS

Abhijit I.

Backend Lead and Architect

Last position:

Lead Backend Developer and Architect at Gloresoft GmbH

I have worked across multiple international client projects, holding senior roles including Software Architect, Senior Software Developer, Technical Lead, and Lead Backend & DevOps Engineer. My experience spans complex enterprise environments in banking, financial services, telecommunications, engineering, and automotive domains, supporting organisations such as UniCredit Bank, Telefónica O2, and BMW.

At UniCredit Bank, within the Securities Domain Transformation program, I led the modernisation of legacy monolithic systems into cloud-native Spring Boot microservices and an Angular frontend deployed on Google Cloud Platform. Beyond implementation, I was responsible for defining the target architecture, producing system architecture diagrams and sequence diagrams, and preparing API contract documentation for clients. I designed RESTful APIs and integrated Apigee for secure and reusable cross-project service consumption of APIs. I architected Kubernetes-based deployments using Helm. CI/CD pipelines were built with Jenkins, automating code analysis using Sonar, as well as testing and deployment stages. Defining clean coding principles for the project, conducting regular code reviews, and mentoring junior developers were also among my tasks at UniCredit.

At Telefónica O2, I led the transformation of a legacy call centre desktop application into a cloud-native microservices and micro-frontend solution. I actively contributed to the platform architecture, creating system architecture diagrams, component diagrams, architecture documentation, and ADRs for future references. I improved the performance and scalability of the services. I optimised AWS infrastructure costs, particularly by minimising the use of DynamoDB and reusing test environments effectively. Observability was implemented using Prometheus, Grafana, CloudWatch, and Splunk dashboards. CI/CD pipelines were delivered using GitLab, Docker, Kubernetes, and AWS. Conducted techinical sessions for teams.

Ivan D.

Technical Lead - IDE Platform