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D

DefSecurity Systems Services · 1001-5000 · B2B contacts & data

5,000 Employees
1958 Founded
Security Systems Services Industry
Security Systems Services France B2B Est. 1958

Company Overview

Sector Administrative and Support Services
Headcount 5,000 employees (1001-5000)
Company type Self-owned
Headquarters France
Website def-online.com
Last updated 31 Jul 2026

Departments actively hiring 1 department

Engineering and technical

These departments at Def are actively recruiting: a strong signal to time your outreach.

Companies similar to Def

About Def

Def is a Security Systems Services company, based in France. Founded in 1958, the company counts about 5,000 employees. As part of the broader Administrative and Support Services sector, Def operates specifically in the Security Systems Services segment. Def is a B2B company, primarily serving business clients and professional organisations. This profile compiles key information about Def, including industry, size, location, business signals, and B2B contacts, to help sales teams qualify the account and identify the right decision makers before reaching out.

Activity & Market

Def is positioned on the Security Systems Services segment, within the Administrative and Support Services sector. As a B2B company, Def primarily serves business clients and professional organisations. In terms of structure, it is registered as “Self-owned”.

Decision Makers at Def

17C-Level 2VP 51Heads
Decision maker Email Phone

Zeliq has found 70 decision makers at Def. Create a free Zeliq account to access their verified emails and direct phone numbers.

See 70 decision makers on Zeliq →

New decision makers last 6 months

1Heads

1 new decision makers joined Def in the last 6 months, a strong signal to time your outreach.

Contact the new decision makers on Zeliq →

Team Structure headcount by department

Technical
133
Sales
97
Other
96
Operations
91
Project Management
50
Trades
33
Administrative
26
Finance
25

How to prospect Def's departments

Technical

With 133 people, this is the organisation's biggest team, and it is hiring. Technical teams verify claims: public docs, a sandbox or a free tier will do the selling for you.

Sales

With 97 people, this is the organisation's second pillar. These profiles handle outreach daily and respond well to concrete pitches about pipeline, productivity and prospecting tooling.

Other

96 people work in this department. Hard to read from the outside: use a first exchange to map who does what before pushing an offer.

Operations

A team of 91 people. Pitch measurable time savings and error reduction: the metrics this function is judged on.

Project Management

This department counts 50 people. Methodology debates are constant here: anchor your pitch in their existing framework rather than against it.

Trades

33 people work in this department. Field teams first: equipment uptime, planning and site safety are the topics that land.

FAQ Def

What industry does Def operate in?

Def is active in the Security Systems Services industry, specifically in the Administrative and Support Services category.

How many employees does Def have?

Def has approximately 5,000 employees (in the 1001-5000 range). This figure is an estimate to help qualify the account, not a legally certified number.

How do I find contacts at Def?

With Zeliq, you can find the right decision makers at Def, get their verified emails and direct phone numbers, and engage them through targeted multichannel sequences.

Where is Def headquartered?

Def is headquartered in France.

Which departments are hiring at Def?

Hiring is currently active at Def in these departments: Engineering and technical. A useful signal to prioritise and time your prospecting.

Why use this data before prospecting Def?

With Def's firmographics and business signals at hand, you can prioritise the account, personalise your approach, and contact the right people straight away.