# Stefan Lew - Cloud Architect & Software Engineer

> Stefan Lew is an independent cloud architect and software engineer based in Leonding, Austria, specializing in serverless architectures, cloud infrastructure, and full-stack development. With expertise in AWS, TypeScript, and modern development practices, he helps businesses build secure, scalable, and cost-efficient cloud solutions.

## Professional Profile

**Name:** Stefan Lew  
**Location:** Leonding, Austria (near Linz)  
**Business:** Individual consulting and software development  
**Focus:** Cloud architecture, serverless computing, full-stack development, DevOps

**Education:**
- BSc Technical Mathematics, Johannes Kepler University Linz
- Strong foundation in mathematical modeling, optimization theory, and computational methods

**Business Registration:**  
- Member of Wirtschaftskammer Oberösterreich (Chamber of Commerce)
- Division: Information and Consulting
- Category: Business Consulting, Accounting and IT
- UID: ATU81788512

## Core Services

### Cloud Architecture & Consulting
Design and implementation of cloud-native solutions following industry best practices across six key pillars:

- **Operational Excellence**: Automated deployments, infrastructure as code, observability-driven operations, runbook automation, and continuous improvement through metrics-driven insights
- **Security**: Defense in depth, least privilege access, encryption at rest and in transit, security automation, compliance frameworks (GDPR, NIS2)
- **Reliability**: Fault isolation, graceful degradation, automatic recovery, chaos engineering principles, multi-AZ deployments, disaster recovery planning
- **Performance Efficiency**: Right-sizing resources, serverless-first approach, CDN utilization, caching strategies, performance monitoring and optimization
- **Cost Optimization**: Pay-per-use models, resource tagging and allocation, automated scaling, reserved capacity planning, cost anomaly detection
- **Sustainability**: Energy-efficient architectures, carbon-aware computing, resource utilization optimization, minimal waste patterns

**Core Technologies:**
- **Serverless Computing**: AWS Lambda, API Gateway, DynamoDB, Step Functions
- **Infrastructure as Code**: SST (Serverless Stack), CloudFormation, Terraform
- **Event-Driven Architecture**: EventBridge, SNS, SQS, DynamoDB Streams

### Site Reliability Engineering & Operations
Implementing reliability practices that balance feature velocity with system stability:

- **Service Level Management**: Defining and monitoring SLIs (latency, availability, error rate), establishing SLOs aligned with business needs, managing error budgets to balance innovation and reliability
- **Observability**: Distributed tracing, structured logging, metrics aggregation, dashboard design, alerting on symptoms not causes
- **Incident Management**: On-call rotation design, blameless postmortems, incident response automation, communication protocols
- **Toil Reduction**: Identifying repetitive manual work, automation-first mindset, self-healing systems, progressive deployment strategies
- **Capacity Planning**: Demand forecasting, resource provisioning, performance testing, scalability analysis
- **Change Management**: Progressive rollouts, feature flags, canary deployments, automated rollback mechanisms

### Full-Stack Development
End-to-end development of modern web applications:
- **Frontend**: React, TypeScript, Vite, Tailwind CSS, TanStack Router
- **Backend**: Node.js, tRPC, Lambda functions, API development
- **Database**: DynamoDB, SQL databases, data modeling
- **Authentication**: AWS Cognito, OIDC, JWT

### DevOps & Operations
Complete lifecycle management from development to production:
- **CI/CD**: GitHub Actions, automated deployments, preview environments
- **Monitoring**: Sentry integration, CloudWatch, performance tracking
- **Development Environment**: Nix, devenv, reproducible builds
- **Quality**: Biome linting/formatting, TypeScript strict mode

### Organizational Design & Team Effectiveness
Consulting on team structures and interactions that optimize for flow and reduce cognitive load:

- **Team Structures**: Designing stream-aligned teams focused on business value flows, establishing platform teams to reduce cognitive burden, creating enabling teams for capability building, coordinating complicated subsystem teams for specialized domains
- **Interaction Modes**: Facilitating collaboration patterns, implementing X-as-a-Service boundaries, guiding teams through facilitating relationships during transitions
- **Conway's Law Application**: Aligning team boundaries with desired architecture, designing communication structures that support system evolution
- **Cognitive Load Management**: Limiting team responsibilities to sustainable levels, providing clear team APIs, reducing context switching through proper boundaries
- **Fast Flow Optimization**: Removing dependencies and handoffs, enabling autonomous team operation, establishing clear ownership boundaries
- **Platform Thinking**: Building internal platforms that accelerate stream-aligned teams, self-service capabilities, documentation and onboarding automation

## Value Proposition

### Reliability-First Engineering
Build systems that meet business requirements for availability while enabling rapid innovation. Establish quantitative reliability targets through service level objectives, implement automated monitoring and alerting on meaningful indicators, and maintain error budgets that balance feature development with system stability. Create blameless cultures that learn from incidents through structured postmortems and continuous improvement.

### Serverless & Cloud-Native Expertise
Transform infrastructure costs from fixed to variable with serverless computing. Eliminate concerns about hardware security and OS updates while paying only for actual milliseconds of resource usage. Automatic scaling from 10 to 10,000 users without manual intervention. Design event-driven architectures that are loosely coupled and highly scalable.

### Well-Architected Solutions
Every architecture decision evaluated across six critical dimensions: operational excellence through automation, security through defense in depth, reliability through fault tolerance, performance through right-sizing, cost optimization through conscious trade-offs, and sustainability through efficient resource usage. Apply proven patterns and avoid common anti-patterns.

### Team & Organizational Effectiveness
Help organizations structure their teams to optimize for fast flow of value. Design team topologies that reduce cognitive load, minimize dependencies, and enable autonomous operation. Align team structures with desired architecture following Conway's Law. Build internal platforms that accelerate delivery while maintaining standards.

### EU Hosting & Compliance
Specialized in EU-only hosting solutions for legal clarity and data sovereignty. Experience with:
- **Compliance**: NIS2 directive, GDPR, EU data protection regulations
- **Platforms**: AWS EU regions (eu-central-1), Scaleway, other European providers
- **Legal Security**: Data stays under EU jurisdiction, no US Cloud Act conflicts

## Technical Stack

**Languages & Frameworks:**
- TypeScript, JavaScript (Node.js 22+)
- React 19, HTML/CSS
- SQL, NoSQL

**Cloud & Infrastructure:**
- AWS (Lambda, API Gateway, DynamoDB, CloudFront, Cognito, EventBridge)
- Infrastructure as Code: SST, CloudFormation
- Package Management: bun, npm

**Development Tools:**
- Git, GitHub Actions
- Biome (linting/formatting)
- Vite (build tool)
- Nix, devenv (environment management)

**Architecture Patterns:**
- Serverless and event-driven architectures
- Microservices with clear bounded contexts
- CQRS and event sourcing where appropriate
- Circuit breaker and bulkhead patterns for resilience
- Strangler fig pattern for legacy modernization
- Single table design for DynamoDB
- API-first design with tRPC for type safety
- Monorepo organization for code sharing
- GitOps and infrastructure as code
- Observability-driven development

**Methodologies & Practices:**
- Service level objectives (SLOs) and error budget management
- Blameless postmortem culture
- Progressive delivery (canary, blue-green deployments)
- Chaos engineering for resilience testing
- Toil automation and reduction
- Continuous improvement through retrospectives
- Data-driven decision making
- Security by design
- Cost-aware architecture
- Documentation as code

## Expertise Areas

### Mathematical Foundation
Background in technical mathematics provides strong analytical capabilities for:
- **Algorithm Optimization**: Complexity analysis, performance modeling, optimization theory
- **Statistical Analysis**: A/B testing, capacity planning, anomaly detection
- **System Modeling**: Queueing theory for performance prediction, reliability mathematics
- **Data Processing**: Numerical methods, computational efficiency, large-scale data analysis

### Cloud Platforms & Services
Deep experience across AWS service portfolio:
- **Compute**: Lambda, Fargate, EC2, Auto Scaling
- **Storage**: S3, EFS, DynamoDB, ElastiCache
- **Networking**: VPC, CloudFront, Route53, API Gateway, Load Balancers
- **Security**: IAM, Cognito, Secrets Manager, KMS, WAF, Shield
- **Observability**: CloudWatch, X-Ray, EventBridge, SNS, SQS
- **DevOps**: CodePipeline, CodeBuild, Systems Manager, CloudFormation

### Reliability Engineering
Practices for building and operating reliable systems at scale:
- SLI/SLO/SLA framework design and implementation
- Error budget policies and enforcement
- Monitoring and alerting strategy
- Incident response and management
- Capacity planning and forecasting
- Performance optimization and tuning
- Disaster recovery and business continuity

## Contact

**Email:** admin@stefanlew.com  
**Phone:** +43 680 2384761  
**Website:** https://www.stefanlew.com

**Address:**  
Mayrhansenstraße 8b  
4060 Leonding  
Österreich (Austria)

## Optional

- [GitHub Profile](https://github.com/lew): Open source contributions and public repositories
- [Website Sitemap](https://www.stefanlew.com/sitemap.xml): Complete website structure
- [Legal Information](https://www.stefanlew.com/impressum): Full imprint and business details