Amazon SNS Expert in Hamburg

Thorsten B.

Senior Software Engineer

Last position:

Senior Backend Engineer at VTG Rail Europe

traigo is VTG's digital rail logistics and fleet management platform. It processes large volumes of telemetry, mileage, geofence, sensor and wagon-movement events in near real time and provides operational services for rail logistics customers across Europe.

As part of Team Customer Selfcare, I worked on the design, implementation, optimisation and operation of large-scale backend services and event-driven processing pipelines — covering both feature development and operational ownership of business-critical production systems. I also regularly acted as first responder for production incidents, data inconsistencies and performance investigations across multiple distributed services.

Design and implementation of event-driven backend services.
Migration and replacement of legacy processing pipelines.
Development of replay / rebuild mechanisms for large event datasets.
High-throughput asynchronous event processing on SNS / SQS.
Database and query optimisation for PostgreSQL and DynamoDB.
Design of scalable read / write models and aggregation pipelines.
Production troubleshooting and operational support.
Performance tuning and infrastructure scaling.
Design and stabilisation of integration and system tests.
Technical concepts, architecture documentation, and cross-team collaboration.
Support the further development of existing GitLab CI/CD pipelines

Geofence & Wagon Stay Processing

Algorithm to detect vehicles within geofences (entry, exit, dwell time).
Event sourcing with guaranteed chronological order within the affected time window.
Refactored geofence event and wagon-stay processing logic for performance.
Resolved race conditions and event-ordering problems in distributed services; server-side filtering, aggregation and optimised query pipelines.
Repair and replay tooling for corrupted or inconsistent movement data.

Fleet Metadata & Mileage

Modernised the service; migrated storage from DynamoDB to PostgreSQL to improve traceability and accelerate new features.
Scalable mileage aggregation and replay mechanisms.
Read / write models and optimised queries for high-volume mileage calculations.

Sensor & Telematics Integration

Integrated telemetry and sensor processing pipelines.
Snapshot and state-calculation logic for sensor systems.
APIs and persistence models for wagon sensor data; data-quality improvements.
Further development of a service using gRPC for intra-service communication.

Movement Segment Processing & Routing

Migrated services to new movement-segment event streams.
Built replay and rebuild tooling for segment correction.
Optimised throughput and reliability for high-volume event processing.

Condition Monitoring & Wagon Analytics

APIs and backend services for wagon condition monitoring.
Brake-wear prediction processing and wagon analytics functionality.
PostgreSQL views and optimised query models for operational dashboards.

Operational Reliability - First Responder

Investigated production incidents and distributed-system failures; DLQ analysis, replay and operational recovery.
Tuned database performance and AWS infrastructure under production load.
Improved observability, monitoring and operational tooling.
Supported rollout strategies, monitoring and post-deployment stabilisation.

Rizwan B.

Software Developer/Database/Devops

Last position:

Software Developer/Database/Devops at Sutor Bank

Project:

Migration of existing VB6 applications to C# (Web API, web app)
Report development and risk management systems (C#, API interfaces, databases)
Document archive (API interfaces, databases)

Team size: 9 people

Reports for Risk and Credit Management Development and maintenance of report structures to support risk and credit decisions, including data modeling, validation, and automated delivery for business departments.
Migration and maintenance of a legacy system to the latest version of .NET for the asset management system Planning and execution of the modernization of an existing asset management system, including code refactoring, performance optimization, test automation, and sustainable maintenance after migration.
Replacement of the COM-based archive connection with a REST API Redevelopment of the connection of the document archive (HYPARCHIV) to a REST API based on OpenAPI/Swagger, including archiving with index and stamp fields as well as PDF export into the customer portal.
Redesign of payment receipt processing Replacement of an existing Oracle PL/SQL process with a new implementation in C# based on a business concept, including business alignment, data modeling, and test coverage.
Design and implementation of tests, creation of deployment pipelines, and documentation
Further development and implementation of change requests.
Regular code reviews within the team as well as optimization of application scalability and stability

Technologies: C#, .NET 10, ASP.NET, Unit of Work, IoC, Three-Tier Architecture, Entity Framework Core, DB First, Web API, Swagger, OpenAPI, Python, Oracle, HYPARCHIV, Azure, PowerBI, DevOps, AKS (Azure Kubernetes Service), GIT, xUnit, NSubstitute, TypeScript, Vue.js, Pinia,

Methods: agile development using Scrum

Martin W.

Security Auditor

Last position:

Security Auditor at MissionMe

Environment: AWS, Ruby on Rails, GraphQL, React Native
Penetration test for Backend, Android-App and iOS-App

Daniel S.

Senior Software Engineer

Last position:

Senior Software Engineer at energielenker solutions GmbH

Designed and implemented a Python-based ETL pipeline with the Dagster framework to transform raw energy data from heterogeneous sources using InfluxDB and visualizations in Grafana
Defined time-based and dependency-based jobs
Deployed to managed Kubernetes clusters using Helm
Integrated InfluxDB Cloud
Prepared data for use in Grafana, including cleaning, normalization, and time-based resampling in Python
Developed dashboards and visualizations in Grafana
Developed unit tests with mocking using pytest
Set up a CI/CD pipeline in GitLab

Technologies: Python, Dagster, InfluxDB, Grafana, pandas, pytest, REST, CI/CD, GitLab, Container, Kubernetes, Helm, Docker, Cloud

Lars K.

Lead Drupal Developer

Last position:

Lead Drupal Developer at x-tention

Lead Drupal 10 developer for several greenfield projects in the health sector
Drupal architecture in a cloud environment
Setup and maintenance of Gitlab pipelines and Kustomize scripts for Kubernetes deployments
Development of Docker images
Drupal custom module development for clients such as OAuth and FHIR
Drupal frontend theming based on Bootstrap 5 and Single Directory Components
Setup and maintenance of automated Playwright tests

Oliver L.

Developer, Architect

Ahrensburg

Last position:

Developer, Architect at libri GmbH

Role: Developer, Architect
Technologies: java, typescript, golang, spring (boot, web, security, data), Angular, AWS (OpenSearch, Aurora, SNS/SQS, CloudWatch, EC2, IAM), Kubernetes, Terraform, Helm, OAuth, Keycloak, CI/CD, gradlew, Liquibase, Test Driven Development, shell scripting

Taher S.

DevOps Engineer

Last position:

DevOps Engineer at Confidential

Working with developers, security, and operations teams to align requirements
Supporting product owners and development teams in using logging and monitoring solutions based on the Elastic Stack
Developing and standardizing log schemas as well as defining practical standards for observability
Designing and further developing logging architectures for complex, distributed multi-tenant environments
Connecting application and infrastructure logs as well as security tools and metrics
Optimizing data flows and modeling for analysis and reporting purposes
Building automated infrastructures using Terraform/Terragrunt and Ansible
Maintaining and further developing CI/CD pipelines in GitLab as well as automated development environments in Hetzner Robot
Operating and automating Proxmox clusters including Ceph storage
Setting up and operating Kubernetes (k3s) clusters on Fedora CoreOS including base services such as Vault, OpenLDAP, and HA Proxy
Implementing security-critical infrastructures according to BSI baseline protection and securing existing systems
Supporting the operation of solutions in cloud environments (including AWS)
Working in agile teams using Scrum and Kanban
Technologies/ applications: Elastic Stack (Elasticsearch, Logstash, Beats/Elastic Agent, Kibana), Terraform, Terragrunt, Ansible, GitLab CI/CD, GitOps, Proxmox, Proxmox Ceph, Kubernetes (k3s), OpenShift, Helm, Kustomize, Vault, OpenLDAP, HA Proxy, Hetzner Robot systems, AWS, Prometheus, Grafana, Syslog Linux/Windows, Docker, NGINX, Apache Security & Compliance (BSI baseline protection, SIEM/SOC)

Andreas S.

Lead Developer

Last position:

Lead Developer at Software

Extended the document management system with a standard CMIS (Content Management Interoperability Services) interface
Implemented CMIS core services like navigation, access rights, search, CRUD operations, and versioning in Java
Implemented based on RESTful / OpenAPI services
Delivered as a fat-jar and native container image
Deployed on-premises and serverlessly as an Azure Container Application using Terraform
Improved team autonomy through infrastructure engineering and short feedback loops
Established observability with OpenTelemetry, Azure Monitor, and Azure Logic Apps
Introduced Terraform and trunk-based development processes
Ensured quality with BDD tests in C# using SpecFlow and Testcontainers
Created Azure DevOps pipeline integration tests
Introduced cloud deployment processes
Trained staff in cloud and Terraform

Jürgen B.

Software Developer

Wedel

Last position:

Software Developer at Inform AG

Coaching junior developers
Further development and customer-specific extensions of a standard software product (microservices (DDD) and partly monolith)
Interface extensions
Web services
Test automation
Design
Technologies used: Java8, Java17, TypeScript, Python, PostgreSQL, Spring (Integration, Data, Boot), JPA, AWS (Cloud, Lambda, EC2, SQS/SNS), Microservices, Fitnesse/Cucumber, Gitlab

Mark P.

Full-Stack Software Developer, Product Data Import

Last position:

Full-Stack Software Developer, Product Data Import at Otto (GmbH & Co KG)

Manage and operate the product data import services for the Otto merchant
Enhance and maintain the backend systems
Optimize and maintain AWS infrastructure
Build a new product data import API
Design and plan stories and features
Conduct code reviews to ensure code quality and best practices
Analyze and fix bugs
Technologies: Java, Spring Boot, Kafka, AWS, Fargate, Terraform, MongoDB, Mongo Atlas, OpenAPI, GitHub, GitHub Actions, GitHub Copilot, Akhq, Debezium, JUnit, Test Containers, Hexagonal Architecture

Christian H.

Lead Developer / AI Engineer

Last position:

Software Developer / Lead Developer at dpa (Deutsche Presse Agentur GmbH)

Contributed to the development of the Rubix editorial system
Implemented various microservices based on Java, AWS S3, AWS SQS, AWS SNS, and Spring Boot, deployed to AWS ECS and AWS Fargate
Designed and developed AWS Lambdas using TypeScript
Used PostgreSQL in an AWS RDS Aurora cluster and AWS DynamoDB
Implemented continuous deployment with GitLab pipelines
Built an Infrastructure as Code environment with AWS CDK
Set up and maintained a monitoring platform using AWS CloudWatch
Developed various frontend components with Vue.js
Designed the microservice architecture applying Domain Driven Design and GraphQL interfaces

Johannes E.

Senior Application Developer

Last position:

Libri GmbH

Operation and further development of the inventory system for booksellers (Quimus). It is an in-house development by Libri that is sold to customers as Software as a Service. The software is developed in an agile way by two developer teams (about 5 developers each). The software consists of around 25 Java microservices that mainly communicate via messaging and share a common Angular frontend. The application runs on Kubernetes in AWS.
Technologies used: Java 17 & 21, Spring Boot 2 & 3, Hibernate, MySQL, Spring Cloud AWS, Lombok, AWS SQS, AWS SNS, AWS RDS, AWS S3, DynamoDB, Kubernetes, Docker, OpenSearch, Hibernate Search, Liquibase, Gradle, Terraform, Helm, GitLab CI, Keycloak OAuth2, TypeScript, Angular
My focus until December 2023: Connecting additional POS systems to the inventory system. Connecting the data warehouse for report display. Extending existing features (goods receipts, invoicing, item management, ...). Operations and DevOps tasks.
Focus from January 2024: Extracting the product search from the inventory system into a global service to use in other applications. Integrating the product search into the booksellers' online shops (also run by Libri). Importing and providing digital items in the product search.

Sebastian W.

Software Engineer & Consultant