We’re currently hiring for a Freelance Senior Backend / Platform Engineer (Python, Kafka) on a 6 month contract

The role

We’re hiring a senior backend / platform engineer to work on a mission-critical, data-intensive platform.
This is a hands-on role focused on event-driven systems, data modelling, and reliability at scale.

Must-have experience

• 5–8+ years of software engineering experience
• Python as primary language for 5+ years
• Proven experience building mission-critical production systems
• 2+ years Kafka experience, including system design & integration
• Strong experience with FastAPI
• Proven experience in data modelling, data engineering, or data science
• Solid knowledge of microservices, containerisation, distributed systems
• Hands-on experience with Kubernetes
• Strong PostgreSQL experience
• Fluent English
• Netherlands-based and able to work onsite in Rotterdam 2 days per week

Nice to have

• Background in energy, trading, or optimisation
• Experience with mathematical optimisation (e.g. Gurobi)
• Familiarity with .NET / C#
• Experience with Azure DevOps
• Dutch language skills
• Experience mentoring or leading engineers

Contract details & application

• Contract length: 6 months (extension possible)
• Working model: 32-40 hour week / Hybrid – 2 days per week onsite in Rotterdam
• Start: ASAP / short notice preferred

If you’re interested, then please email me your updated CV, minimum required rate and your availability to interview/start.

We’re currently recruiting for a Freelance .NET Backend Engineer on a 6 month contract, starting in the next 4-6 weeks.

Location: Remote / Rotterdam
Contract: Freelance / ZZP / BV
Duration: 6 months (extensions likely) / 32-40 hour week
Start: ASAP (March / early April)
Language: English

Overview

We’re looking for a Senior Freelance .NET Backend Engineer to support a mission-critical energy trading and optimisation platform.

This role sits close to real-time decision-making systems, where performance, reliability, and system behaviour under load truly matter. You’ll work on backend services that ingest, process, and distribute large volumes of data to support trading, planning, and optimisation use cases.

This is not a generalist .NET role.

What You’ll Be Doing

• Design, build, and maintain high-performance backend services in .NET / C#
• Work on event-driven microservices supporting trading and optimisation workflows
• Integrate systems using Kafka / event buses and data-streaming patterns
• Support data ingestion and pre-processing pipelines
• Collaborate closely with Python engineers responsible for optimisation models
• Ensure systems meet high availability and reliability requirements
• Contribute to observability, incident readiness, and production stability
• Operate confidently in environments where small changes can have large system impact

Must have

• 5+ years of strong .NET / C# backend experience
• Proven experience with event-driven architectures
• Hands-on experience with microservices in production
• Cloud-native development experience (Azure preferred)
• Comfortable working with data-heavy systems
• Able to read and understand Python code and collaborate with Python engineers
• Experience with mission-critical or real-time systems
• Based in the Netherlands and fluent in English

Bonus experience

• Experience in energy, trading, or optimisation platforms
• Kafka in production environments
• Kubernetes at scale
• Observability tooling (Grafana, Prometheus, Dynatrace)
• Infrastructure-as-code (Terraform)

Why This Role

• Work on complex, real-world systems
• High-impact role with genuine production responsibility
• Strong engineering culture
• Meaningful contribution to the energy transition

If you’re interested then please apply within. Consultancy candidates are NOT welcomed for this role.

Freelance Senior UX/UI Designer – Data Visualization & Reporting

• Hybrid (Amsterdam / Remote)
• 6-month SOW
• Feb 2026 Start

If you’re passionate about designing data-driven experiences that turn complex information into clear, actionable insight — this role is for you.

We’re looking for a Freelance Senior UX/UI Designer with strong expertise in data design, dashboards, and reporting to help shape how organisations understand and act on their data.

What you’ll be doing

• Designing intuitive dashboards, analytics tools, and reporting interfaces
• Turning complex datasets into visually engaging, decision-ready experiences
• Working closely with product managers, data teams, and engineers
• Contributing to scalable design systems and data-visualisation standards

What we’re looking for

• 5+ years’ experience in UX/UI design, with a strong focus on data visualisation or analytics tools
• Proven B2B enterprise reporting experience (HR, finance, wellbeing, or other data-heavy domains)
• Strong Figma skills (design systems, prototyping, handoff)
• Familiarity with Power BI, Tableau, or similar data-visualisation tools
• A systems-thinking mindset — clarity, consistency, scalability
• Confident communicator in cross-functional teams

Why join?

You’ll be working on meaningful, insight-driven products that help organisations make better decisions — and designing experiences where data truly matters.