Our Tech Stack
The right tool. For every problem.
We are not framework fans, but problem solvers. Here you can see which technologies we work with daily and what we use them for. We make choices based on your requirements, not the latest hype.
Frontend & Web
Fast, accessible interfaces for portals, platforms, and websites. From enterprise portals with Angular to high-performance content websites with Astro – we choose the framework that fits your product and your team.
In use:
Angular, React, Next.js, Astro, Svelte, Qwik, TypeScript, TanStack, RxJS & NgRx, Tailwind CSS, Material UI, shadcn/ui, Storybook, Nx
Backend
Scalable services and business logic that will still be maintainable in five years. TypeScript in the backend, Java and .NET for enterprise landscapes, Go where performance matters.
In use:
Node.js, NestJS, Java & Spring Boot, Kotlin, Scala, .NET & C#, Go, Python, hapi, LoopBack, Hibernate, Flyway
APIs & Integration
We connect your systems: ERP, CRM, shop, and portal. API-first, well-documented, and automated testing – so data flows instead of being copied via Excel.
In use:
REST, GraphQL, OpenAPI & Swagger, Apicurio, Microcks, Postman, Bruno, Mailgun
Connected:
SAP, Microsoft Dynamics 365, Salesforce, HubSpot, Odoo
Mobile & Cross-Platform
One codebase for iOS, Android, and web. With Flutter, we deliver native performance without double the development effort – together with our partner marQably, who works desk-to-desk with us.
In use:
Flutter, Dart, Bloc, Riverpod, Firebase, Supabase, Swift, Kotlin, Electron
Headless CMS & Commerce
Manage content once, distribute everywhere. We rely on headless systems without vendor lock-in – and on commerce platforms that can handle complex B2B requirements.
Headless CMS:
Strapi, Directus, Payload, Storyblok, Prismic, Sanity, Contentful
Commerce & Payment:
Vendure, Shopify, Stripe, Adyen, Mollie, PayPal, Klarna
Data & Analytics
From the database through the pipeline to the dashboard: We make data usable – for real-time monitoring, reporting, and forecasting.
In use:
PostgreSQL, MongoDB, MySQL, Oracle, SQL Server, Redis, ClickHouse, DuckDB, Neo4j, Apache Kafka, Apache Airflow, Apache Spark, Databricks, BigQuery, Metabase
AI & Machine Learning
AI that works in everyday life: LLM integration, RAG, and agents – with cloud models or locally operated open-source models, if your data shouldn't leave the house.
Models & Frameworks:
OpenAI, Anthropic Claude, Mistral, DeepSeek, Qwen, Ollama, Hugging Face, LangChain & LangGraph, LlamaIndex, Chroma, Neo4j
AI in development everyday:
GitHub Copilot, Microsoft Copilot, Claude Code, Cursor
Cloud, DevOps & Monitoring
Automated pipelines, reproducible deployments, and monitoring that reports problems before your customers do. Cloud or on-premise – we are vendor-independent.
Infrastructure & Cloud:
Docker, Kubernetes, OpenShift, AWS, Microsoft Azure, Google Cloud, Hetzner, Dokploy, Coolify
CI/CD & Monitoring:
GitHub Actions, GitLab CI, Jenkins, Argo CD, Grafana, Prometheus, Elastic Stack (Elasticsearch, Logstash, Kibana)
Identity & Security
One login for all applications. We integrate single sign-on securely into existing landscapes – with open-source solutions or cloud identity providers.
In use:
Keycloak, Authentik, Zitadel, FusionAuth, Auth0, Microsoft Entra ID (Azure AD), Google Workspace, OAuth 2.0 & OpenID Connect, LDAP
Quality & Collaboration
Automated tests secure every delivery. And because software is teamwork, we work in the tools your teams already know.
Testing:
Playwright, Cypress, Jest, JUnit, Selenium, Supertest
Collaboration:
Jira, Confluence, Slack, Microsoft Teams, Miro, Figma
Frequently Asked Questions
[] Which tech stack does LEAN-CODERS work with?
Our focus is on TypeScript with Angular, React, and Node.js/NestJS, Java/Spring Boot, and .NET in the backend, Flutter for apps, headless CMS like Strapi and Directus, as well as Docker and Kubernetes for operation. Additionally, we offer data, AI, and identity solutions – depending on the project.
[] What is a tech stack and how do you choose the right one?
A tech stack is the combination of programming languages, frameworks, databases, and infrastructure used to build and operate software – for example, Angular in the frontend, NestJS in the backend, PostgreSQL as the database, and Kubernetes in operation. The right stack is chosen based on the product's requirements, the team's expertise, hosting guidelines, and long-term maintainability. LEAN-CODERS does not recommend a stack based on a template, but justifies every decision.
[] Which software company in Vienna develops with Angular, React, Node.js, and Flutter?
LEAN-CODERS is a software development company based in Vienna (Hainburger Straße 33, 1030 Vienna). We develop custom software, customer portals, web apps, and cross-platform apps with Angular, React, Node.js/NestJS, Java/Spring Boot, .NET, and Flutter – for companies in Austria and the DACH region.
[] How do you decide which technology we use?
Based on your requirements, not hype. We consider team size, existing infrastructure, hosting preferences, budget, and above all, maintainability. In the end, your team should be able to continue developing the software without us.
[] Angular or React: Which is better for enterprise applications?
Both frameworks are mature. Angular comes with routing, forms, and dependency injection, making it suitable for large, long-lasting enterprise applications worked on by multiple teams. React is more flexible and has a larger ecosystem, such as Next.js for search engine-relevant websites. LEAN-CODERS works with both and decides based on team size, existing codebase, and requirements.
[] Flutter or React Native: Which framework is right for our app?
Both allow for a shared codebase for iOS and Android. Flutter excels with consistent presentation across all devices and high performance, while React Native benefits from its proximity to the React ecosystem if your team is already using React. LEAN-CODERS primarily relies on Flutter for cross-platform apps – together with our partner marQably.
[] What is a headless CMS and when is Strapi worthwhile?
A headless CMS separates content management from presentation: content is managed once and delivered via API to websites, apps, or other channels. Strapi is an open-source headless CMS that can be self-hosted and flexibly extended – ideal if you want full control over data and hosting. Depending on requirements, LEAN-CODERS also uses Directus, Payload, Storyblok, or Contentful.
[] What is Keycloak and why do you need single sign-on?
Keycloak is an open-source solution for identity and access management. With single sign-on, employees or customers log in once and have access to all connected applications – safer and more convenient than many individual passwords. LEAN-CODERS integrates Keycloak, Authentik, Zitadel, or Microsoft Entra ID into existing system landscapes, including connections to Active Directory and LDAP.
[] Can AI like ChatGPT be used in compliance with data protection in companies?
Yes, with the right architecture. Open-source models that run on your own infrastructure with Ollama, ensuring no data leaves the company, or cloud models in European data centers are possible. LEAN-CODERS builds AI solutions like RAG systems and agents to meet your data protection requirements. Legal assessments are conducted together with your data protection officers.
[] Do you rely on open source?
Where it makes sense, yes – for example, with Strapi, Directus, Payload, Keycloak, or Vendure. This means: no vendor lock-in and your data remains under your control. We use commercial cloud services when they are the better choice for your case.
[] Do you only work with the technologies on this page?
No. The page shows our focus areas. We also familiarize ourselves with existing stacks and take over systems built by others.
[] Can you modernize a system with outdated technology?
Yes. Whether AngularJS, older .NET versions, or legacy monoliths: We migrate step by step to a modern stack, without a big bang and without jeopardizing ongoing operations.
[] How does the onboarding process for a project with LEAN-CODERS work?
Typically with a pilot phase of 4 to 12 weeks and a clearly defined scope. In the end, there is no concept paper, but functioning code – tested and deployed. Based on this, you decide whether to scale, adjust, or stop.
[] What does custom software development cost?
This depends on scope, complexity, and necessary integrations. At LEAN-CODERS, you start with a time-limited pilot based on effort (Time & Material), optionally with a cost cap. This way, you always see what you are paying for – without fixed-price risk and without lock-in.
If you still have questions, just contact us
Tell us about your project. We will honestly tell you which technology fits – and which does not.
Which stack fits your project?
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