Better decisions with your own data.

I build maps, analyses and GenAI tools for organisations, and I teach teams to do the same. Tell me what you need and I'll reply within 2 business days.

Josep Ferrer

What do you need?

A data project

For public bodies, research groups and companies that have the data and need a decision, a tool or a story out of it.

Monthly

Retainer

I join your team part-time as an external data person. Python, SQL, D3.js, Power BI, Tableau, cloud and LLMs.

Example: NECSTouR, since 2024

I work freelance and part-time, so I don't take full-time roles.

How it works

  1. You write to me or book a call

    Tell me what you need in a few lines, or pick a 20 minute slot.

  2. I send a one-page proposal

    Scope, timeline and price, within a few working days.

  3. We do the work

    Short check-ins along the way. You keep the results, the code and the tools.

Recent projects

popgrid explorer
Open source. 2026

popgrid: every country as equal blocks

An open-source Python library that redraws any country as blocks, where each block is an equal share of land, people or GDP. It powers my weekday map series: 35 countries so far.

Catalonia Income Atlas
Public project. 2025

Catalonia Income Atlas

Income inequality across 5,108 census tracts, from INE data for 2015 to 2023. It shows where income is lowest at census-tract level.

Open the atlas →
NECSTouR. Ongoing

A shared data API for European tourism regions

An API and dashboards that bring public tourism and mobility data into one place for the network's regions, plus LLM pilots and training for their teams.

PythonDjangoSupersetLLMs

See all public projects →

What clients say

Consistently delivering high-quality work and meeting our deadlines. Josep has a rare ability to turn complex topics […] into clear, engaging, and accessible guides.
Axelle DervauxMarketing Director, ClicData, after 12 months of technical writing

A workshop, webinar or talk

For teams, universities, training providers and event organisers. Online or on-site, in English, Spanish or Catalan.

1 day

Team workshop

Your team works on its own data: how to analyse it with GenAI, what to trust and how to present it.

1 to 2 hours

Webinar or talk

Data visualization, maps with Python or GenAI at work, for your event, community or company.

Several weeks

Course

Hands-on courses for universities and training providers. I teach in the Big Data Master at Universidad de Navarra and lead GenAI for Professionals at Emeritus.

So far: 350+ master's students, 150 professionals and 1,000+ webinar attendees.

How it works

  1. You tell me the audience

    Who it is for, the format and the date you have in mind.

  2. I send an outline and a price

    One page, within a few working days.

  3. I deliver the session

    Online or on-site. You keep the slides and materials.

Where I teach and speak

Sponsorship

For companies that want to reach data and AI professionals.

Where it runs

Per map

Sponsored map

Your brand on one of my weekday maps on LinkedIn and X, clearly labelled. The maps have passed 1 million views in a week on LinkedIn.

Per issue

Newsletter slot

One sponsor per issue of databites, sent to 10k readers.

Per post

Sponsored post

A post about your book, course or tool on LinkedIn and X, with my own photos and my own take.

How it works

  1. You tell me the product

    What you want to promote and when.

  2. We agree format, date and price

    A map, a post or a newsletter slot.

  3. I publish it

    Clearly labelled as sponsored. Afterwards I send you the numbers.

Examples

Technical writing

For data and AI companies that need tutorials and articles written by someone who uses the tools.

3 months minimum

Monthly package

2 to 5 pieces a month, 1,500 to 2,500 words each, with research and two revision rounds.

Languages

English, Spanish or Catalan

Invoiced in EUR or USD, 30 days net.

How it works

  1. You tell me what you need

    Topics, audience and how many pieces a month.

  2. We agree the package

    Pieces per month, deadlines and price.

  3. I become your external technical writer

    I deliver every month, with two revision rounds per piece. You publish with or without my byline.

Samples

See all nine samples and the full terms →

What clients say

For more than 12 months, Josep has been our main writer for technical blog articles, consistently delivering high-quality work and meeting our deadlines. Josep has a rare ability to turn complex topics, from data management and infrastructure to strategy, into clear, engaging, and accessible guides.
Axelle DervauxMarketing Director, ClicData
Josep took on some of the most technical topics we covered: LLM evaluation, RAG pipelines, agentic RAG, guardrails for AI agents, prompt versioning, and document parsing with OCR. The first piece Josep wrote for us was strong enough that we used its structure to test a new format for the blog.
Dave DaviesPrincipal SEO Manager, CoreWeave (Weights & Biases)
NECSTouR Universidad de Navarra Universitat Pompeu Fabra TIDE research group DATAI Emeritus DataCamp Weights & Biases Stack AI ClicData

Questions

Where do you work?

From Rotterdam, online across Europe. On-site work is possible in the Netherlands, Spain and nearby countries, with travel agreed in the proposal.

Which languages?

English, Spanish and Catalan, for the work itself and for everything I deliver.

How is it invoiced?

In EUR, from the Netherlands. If your organisation needs a formal quote for a procurement process, I'll prepare it.

What happens with our data?

It stays under your control. I work within your data policies and I'm happy to sign an NDA. Nothing is shared or published without your approval.

Can you join a funded project?

Yes, as an external expert or subcontractor in EU-funded projects such as Horizon Europe or Interreg.

Tell me what you need.

Use the form or email me. I reply within 2 business days.

Email
josep@databites.tech