Software, cloud and AI, designed and built by the engineer you talk to.

Lesierse IT is an independent studio for application development and consultancy. More than twenty years of building software, now available for your product, your platform or your team.

System context · Lesierse IT
You [Person] A business with something to build, or a team that wants to move faster.
Lesierse IT [Software studio] Application development and consultancy
Your application [Web · mobile · API]
Your platform [AWS · Azure · AI]
Ace31 [Own app · iOS · Android]

Four things, done properly.

Hire Lesierse IT to build, to advise, or both. Engagements range from a focused architecture review to delivering a complete application.

Application development

[Service: design, build, ship]

From idea to production: web applications, APIs, integrations and back-ends, built to be maintained by the next developer, not just to pass the demo.

  • .NET / C#
  • TypeScript
  • Web & mobile
  • APIs & integrations
  • Multi-tenant SaaS

Cloud

[Service: architecture & migration]

Cloud platforms that are secure, automated and affordable. New builds, migrations, and modernising legacy systems into cloud-native services.

  • AWS
  • Azure
  • Kubernetes
  • Infrastructure as code

AI

[Service: integration]

Practical AI inside real products and workflows: language models, retrieval over your own data and agents, with attention to cost, quality and privacy.

  • LLMs
  • RAG
  • Agents
  • AI-assisted development

Consultancy

[Service: architecture & engineering practice]

A senior second opinion or an extra pair of hands. Architecture reviews, technical due diligence, DevOps and delivery practices, and coaching teams through change.

  • Architecture reviews
  • DevOps & CI/CD
  • Modernisation roadmaps
  • Team coaching

Lesierse IT [Software studio]

Ace31 app icon

Own apps, like Ace31.

Lesierse IT doesn't only advise. It also designs, builds and ships its own apps, such as Ace31: the classic card game 31 for iPhone, iPad and Android. Built end to end, the same way client work gets done.

  • Play against 1 to 5 AI opponents that think and make mistakes like real players.
  • Plays fully offline. No ads, no accounts, no data collection.
  • Available in English, Dutch, German, French and Spanish.
View Ace31 on the App Store

Twenty years of shipping software.

Developer, architect and consultant across start-ups, scale-ups and large organisations. The experience behind every engagement:

Software engineering
.NET and C# at heart, comfortable across TypeScript, Python, Go and Java. Full-stack: front-end, APIs, data and integrations.
Cloud architecture
Designing and running workloads on AWS and Azure: cloud-native services, security, cost and reliability.
Modernisation
Taking large legacy systems to the cloud and from monolith to services, including multi-tenant SaaS platforms, without stopping the business.
Platform & DevOps
Containers and Kubernetes, infrastructure as code with AWS CDK and Terraform, CI/CD pipelines and observability.
AI
Putting language models to work in products and in the development process itself, from prototypes to production.
Community
Open-source contributor and conference speaker on cloud development and infrastructure as code.

How an engagement runs.

No layers of account managers. You work directly with the person who designs and writes the code.

  1. Conversation

    You explain the goal and the constraints. I ask the awkward questions early.

  2. Proposal

    A clear scope, approach and deliverables, so you know what you get before work starts.

  3. Build

    Short iterations with working software early and visible progress throughout.

  4. Hand-over or run

    Documented and automated, then handed to your team, or kept running for you.

Have something to build?

Tell me about your product, platform or team. Every message is read and answered personally.

build@lesierse.it
Email
build@lesierse.it
LinkedIn
Vincent Lesierse
KvK
42185604
BTW
NL003590651B55