Blog
Notes on reaching your staff
How staffing agencies actually reach their flex pool: research, practice and product notes from the Boomer team.

Guide
Can you message your staff on WhatsApp? What the GDPR allows
Messaging your flex pool is allowed, but consent is usually the wrong legal basis. What does work, and why that group chat is your biggest risk.
Tijn van Geel · 13 August 2026
Guide
WhatsApp gets more expensive on 1 October: what you can do
The Netherlands is one of the most expensive countries for WhatsApp messages, and from 1 October 2026 your replies are no longer free. What it costs.
Tijn van Geel · 13 August 2026
Guide
Setting a PIN for your WhatsApp Business number: how to prevent a takeover
Verification codes you did not request, or suddenly logged out? Someone is trying to take over your number. Here is how to switch on two-step verification.
Aron Heesakkers · 27 July 2026
Comparison
Boomer vs. Trengo: which one fits how you use WhatsApp?
Trengo is an omnichannel customer service inbox. Boomer is built to reach and schedule your flex pool. How to pick the right one.
Aron Heesakkers · 26 June 2026
Guide
Getting WhatsApp Business for your flex pool: a step-by-step guide
How do you get WhatsApp Business set up for hundreds or thousands of workers? The difference between the app and the platform, and how to start safely.
Aron Heesakkers · 25 June 2026
Guide
WhatsApp Business with multiple users: how to set it up
Can WhatsApp Business work with multiple users? Not with the free app, but it does on the platform. Here is how your whole team works on one number.
Aron Heesakkers · 24 June 2026
Guide
WhatsApp number blocked? Here is why, and how to prevent it
Your WhatsApp number is blocked and your flex pool is unreachable. Why it happens, what to do now, and how to stop it happening again.
Aron Heesakkers · 23 June 2026
Guide
WhatsApp Business templates: 7 examples for your flex pool
What are WhatsApp Business templates and what do good ones look like? Seven templates for reaching your flex pool, plus Meta's rules.
Aron Heesakkers · 22 June 2026
Engineering
Never losing your number: the engineering behind a channel that holds
Four SIM cards and a private number is not an architecture, it is a delay. How to build a recruiting channel that stays standing at any volume.
Aron Heesakkers · 15 June 2026
Engineering
How our AI knows what to answer
A language model knows everything about the world and nothing about your agency. The difference is the context you give it.
Aron Heesakkers · 20 May 2026
Engineering
An AI that actually understands your workers
A chatbot that only gives you text back is a toy. An agent that checks your schedule, books a shift and confirms it is a colleague. Here is how we built that.
Aron Heesakkers · 8 April 2026
Vision
How do you build a product that scales without buckling?
How do you meet every customer request without losing sight of your vision? It is a question every growing software company wrestles with.
Tijn van Geel · 23 November 2025
Research
Workers do not want an app, they want to message
Contact with young workers only really works when it is human, personal and direct.
Floris Lugtmeijer · 14 October 2025
Vision
Hi Boomer!
We all know how a good team feels: the communication takes care of itself. Personal contact motivates, and it is why someone goes the extra mile.
Floris Lugtmeijer · 4 October 2025