Mikkel Rostved

All cases

A selection of work I've done. All cases are anonymised out of respect for my clients.

YearAreaProjectTechnologies
2026Data & API
Decoupling systems through an APIA central automation job read directly from another system's database.
What I did

New API endpoints and the job rewritten to use them, with extensive automated tests and data comparison before rollout.

  • PHP
  • Node.js
2026Cloud & infrastructure
From Supabase Cloud to an EU-hosted platformA new system built on Supabase Cloud had to move to EU-based hosting because of data requirements.
What I did

Built the entire platform from scratch: Supabase adapted to managed PostgreSQL, serverless containers and object storage, staging and production in OpenTofu, integrations through edge functions, CI/CD with security gates, and a security analysis of the system.

  • Scaleway
  • OpenTofu
  • Supabase
  • PostgreSQL
  • GitHub Actions
2026Data & API
From polling to webhooks in an IoT pipelineData from a hardware vendor was fetched by polling and needed to be pushed in via webhooks instead.
What I did

Helped the vendor change their pipeline, built the webhook receiver and a parser for an undocumented format - validated by running the new and old pipelines in parallel and comparing output.

  • Node.js
  • AWS Lambda
  • AWS ECS
  • TimescaleDB
2026Cloud & infrastructure
Greenfield platform for a new applicationA new application needed production and staging environments from scratch.
What I did

Infrastructure as code with a managed database and serverless containers, logging and monitoring, CI/CD, and adapting AI-generated parts of the application to the platform.

  • Scaleway
  • Terraform
  • OpenTofu
  • GitHub Actions
2025–2026Upgrades
Migrating a legacy application to a modern platformAn older application had to be upgraded to stay supported.
What I did

Upgraded the framework through several versions, automating where possible, and made sure everything kept working.

  • PHP
  • Symfony
  • Rector
  • PHPUnit
  • Claude Code
2025Data & API
Event-driven asynchronous pipelineData processing jobs needed to run asynchronously without blocking or bloating existing workers.
What I did

An event-driven pipeline reusing existing processing code, automatically spawning workers and bringing job queues into the existing workers.

  • RabbitMQ
  • Kubernetes
  • Python
  • PHP
  • Helm
2025Cloud & infrastructure
Batch jobs moved onto a container platformLots of web-based cron jobs needed modernising and moving.
What I did

A wrapper reusing existing scripts unchanged, optimised images and a template system so new jobs need minimal configuration.

  • Kubernetes
  • PHP
  • Docker
  • Helm
  • GCP
  • GKE
2025–Data & API
API for storing and serving IoT dataAn API able to handle large volumes of sensor observations.
What I did

Built for performance with caching and a time-series database, container orchestration, CI/CD and a client SDK for integrations.

  • Go
  • Redis
  • PostgreSQL
  • TimescaleDB
  • Kubernetes
  • GKE
  • K3s
  • Cloud Build
  • PHP
2025Software development
Custom features and refactoring of a SaaS platformA large client needed tailored features in two SaaS web applications.
What I did

Built the features and refactored along the way to remove duplication and bring the code up to new coding standards.

  • PHP
  • MySQL
2024–2025Security
Security test of a SaaS web applicationA thorough security assessment of a SaaS web application.
What I did

Penetration test using both automated tools and manual testing of authentication, authorisation, input validation and more, following OWASP WSTG.

  • Burp Suite
  • OWASP ZAP
  • OWASP WSTG
  • PHP
2023–2024Security
IoT hardware security assessment and device managementA security assessment of the client's hardware devices, plus a system for managing gateways and sensors.
What I did

Security analysis of the devices, a device-management proof of concept, a hardware configurator prototype, secure remote access to gateways and a backend for bootstrapping new devices.

  • LoRaWAN
  • Raspberry Pi
  • OpenVPN
  • GCP
  • Python
2023–2024Software development
Multi-tenant web application from scratchA new system for submissions from users across different organisations.
What I did

User interface, admin module and REST API - running on managed databases and serverless compute.

  • Ruby on Rails
  • GCP
  • Cloud SQL
  • Cloud Run
  • REST
2023–2024Cloud & infrastructure
Container platform and migration of 40+ servicesThe client needed to modernise their infrastructure.
What I did

A container platform from scratch with development, staging and production environments, tooling that makes deployments easy for developers, and migration of every service off several legacy platforms.

  • AWS ECS
  • Fargate
  • CDK
  • Docker
  • Node.js
  • Go
2023Software development
Hybrid mobile apps for data visualisationiOS and Android apps for viewing sensor data.
What I did

Hybrid apps with login, charts and a multilingual interface - plus specifying and helping build the backend API.

  • Ionic
  • Angular
  • TypeScript
  • REST
2023–Data & API
End-to-end data pipeline, infrastructure includedAn API receiving data from an external vendor via webhooks, an event database, transformation jobs converting it into time series, and an API for querying them.
  • Node.js
  • TypeScript
  • TimescaleDB
  • AWS ECS
  • Docker
2022–2023Upgrades
Runtime upgrade and platform switchAn unsupported runtime version, and a wish for more modern hosting.
What I did

Upgraded to the latest runtime, adapted the architecture to the new platform's routing and set up separate test environments before switching.

  • PHP
  • App Engine
  • GCP
2022Cloud & infrastructure
Cloud infrastructure and application migrationA web application had to move to a cloud platform.
What I did

The whole cloud infrastructure from scratch - databases, storage, deployment pipelines and security - plus adapting the application and migrating data.

  • Ruby on Rails
  • GCP
  • PostgreSQL
  • Docker
2022Software development
Making an existing web application multi-tenantA web application built for a single organisation needed to serve many.
What I did

Upgraded to the latest framework version and built in multi-tenancy with full data isolation between organisations.

  • Ruby on Rails
  • GCP
  • Cloud Run
  • PostgreSQL
2022Automation
Automating user account processesAccount creation and notifications needed to be automated.
What I did

An event-driven service listening to database events, triggering account creation and integrating with the existing identity system - with CI/CD.

  • Kubernetes
  • Python
  • PostgreSQL
  • Keycloak
  • GitHub Actions
2022Upgrades
Identity platform upgradeAn outdated installation of the identity system that no longer received updates.
What I did

Upgraded the installation, set up a separate staging environment and automated deployments to both environments.

  • Keycloak
  • Docker
  • GitHub Actions
2021Upgrades
Infrastructure migration to a newer runtimeThe infrastructure needed a newer runtime to keep receiving security updates.
What I did

Migrated the whole stack and moved to containers at the same time, ready for a modern container platform.

  • Chef
  • AWS OpsWorks
  • PHP
  • Ubuntu
  • Docker
2021Upgrades
Web framework upgradeA large web application on an unsupported framework version.
What I did

The whole codebase lifted to the latest version with automated refactoring, and everything verified afterwards.

  • Symfony
  • PHP
  • Rector
2019Cloud & infrastructure
Infrastructure for an IoT data pipelineA new data pipeline with a message broker, a service and a database needed somewhere to run.
What I did

Infrastructure for the whole pipeline and automated deployment of the service.

  • MQTT
  • GCP
  • Docker
2018–Cloud & infrastructure
Cloud environment from scratch for a SaaS platformAn existing web application needed to run in the cloud.
What I did

A new cloud environment with managed databases, storage and scheduled jobs, the application adapted to the platform, and automated releases.

  • GCP
  • App Engine
  • PHP
  • MySQL
2018–Cloud & infrastructure
Ongoing cloud cost optimisationCloud spend had to keep pace with actual need as the platform grows and changes.
What I did

Ongoing analysis and capacity adjustments together with the developers, changes in code and configuration, consolidation and committed-use discounts. Have achieved multiple savings of 20-25% after discounts.

  • GCP
  • FinOps
2016Software development
Web application for order managementHandling take-away orders with custom menus.
What I did

Order flow, reporting and administration - deployed with infrastructure as code.

  • PHP
  • Symfony
  • PostgreSQL