The conversation comes up in almost every demo with an agency or an IT services firm already running an ATS. The leader listens, nods, then asks the only question that matters in their eyes: will they have to change tools, migrate the database again, retrain the recruiters. The answer fits in one word, no, and this article explains why. An ATS-connected HR Hub does not replace your ATS. It sits on top, plugs into it, and finally makes useful a set of data that your current pipeline stores without ever reactivating.
The term deserves to be defined properly, because it is easy to confuse it with yet another recruitment tool. A Hub, in the sense we mean here, does not add one more place to enter applications: it reads what your tools already contain, writes back what it produces, and connects sources that today do not talk to each other.
The ATS does its job, the isolation of its data is the real bottleneck
Let us start with some good news rarely said out loud: the ATS market is mature and adoption is progressing. According to APEC, half of large companies used recruitment software in 2024 for their executive hiring, twelve points more than in 2021. At the top of the market, adoption is massive: according to a sector mapping by Auxine Partners citing Exaegis Markess and Xerfi, more than eight large companies out of ten (CAC 40, SBF 120) have an ATS, while SMEs and mid-caps remain largely under-equipped. In value, still according to this source, HR software and services approached 5 billion euros in revenue in France in 2024, up nearly 12 percent, and the ATS market alone already counts more than 150 players.
In other words, if you are an agency or an IT services firm, you have probably already done the hardest part. The tool is in place, the recruiters know it, the pipeline lives in it. That is not where the problem is.
The problem appears when you look at what these tools do together, which is to say almost nothing. A study cited by Culture RH reports that 92 percent of companies only partially integrate their HR applications with their operations, that 64 percent of teams run into difficulties consolidating their data, and that seven HR departments out of ten take several days to produce a simple report. A candidate's data lives in the ATS for the process status, in email for the exchanges, in the sales CRM for an agency that bills, on LinkedIn for sourcing, and in a video file or a note for the interview itself. Five places, no seam between them.
This scattering has a direct effect on what matters most to an agency or an IT services firm: the ability to surface a candidate already met. When data is fragmented, the talent pool never gets reactivated, you start from zero on every role. That is the subject our article on why the talent pool lies dormant covers in detail, and it is also what the field teams describe.
The talent pool is a disaster, badly structured, evaluations barely filled in, labels unused.
This observation is not a flaw in the ATS. An ATS does well what it is designed for, tracking applications by role and by status. It was never meant to connect your five sources or to make searchable what was said during an interview.
System of record and system of engagement: two roles, not two rivals
The useful distinction here was formalized fifteen years ago by Geoffrey Moore and AIIM, outside of recruitment, to describe enterprise IT. On one side the system of record, the reference system, the one that holds the official and durable truth: who this candidate is, on which role, at which status. On the other side the system of engagement, the day-to-day usage system, the one that sits on top to provide access, collaboration, intelligence. According to the original AIIM definition, these engagement tools layer over systems of record and complement them, without replacing them.
Transposed to recruitment, the ATS is your system of record. It is the one that stays master of the candidate profile, the status, the compliance of the pipeline. The Hub is a system of engagement placed on top: it does not try to hold the truth in place of the ATS, it enriches it and makes it usable day to day. This separation of roles is what makes it possible not to migrate. You keep your reference database, you add a layer of usage.
It is also the logic followed by the departments that rationalize their HR data without breaking everything. Setting up data governance, as a column in the Journal du Net reminds us, does not mean replacing the existing tools, but adding an orchestration layer between applications that keep being used. The HR Hub applies this principle to the scope of recruitment and interviews.
Read, write, synchronize: the three flows of a connected Hub
The word "connected" covers three different technical realities, and the nuance changes everything for a DPO as much as for a leader. Better to name them clearly.
The read flow
The Hub reads from the ATS. It pulls the candidate profile, the associated job, the process history, to present the recruiter with full context without having to juggle two screens. A read-only flow is low-risk and already useful, but it leaves the ATS unchanged: what the Hub learns during the interview stays in the Hub.
The write flow
The Hub writes to the ATS. The interview summary, the structured criteria, the evaluation, flow back into the candidate profile of your system of record, in the right format, in the right place. This is the flow that avoids double entry and that keeps information from dying in an isolated note. The recruiter runs the interview, the Hub structures it, and the ATS ends up enriched with no manual effort.
The bidirectional flow
Both, both ways, in sync. The Hub reads the context before the interview and writes the enriched profile back afterward. This is the most useful mode, and it is also where the technical difficulty concentrates. Integration practitioners point it out, most of the pain sits at this seam, because you have to map two data models, handle conflicts, respect permissions. That is the work of a serious Hub: absorbing this complexity so you never see it.
Bidirectional enrichment of the candidate profile, in practice
Let us leave the abstract. A consultant runs a technical interview at an IT services firm for a cybersecurity qualification assignment. Today, without a Hub, here is what happens: the recruiter takes notes in a corner, vaguely fills in a comment field in the ATS, forgets to tick the skills, and the essence of what was said, the real availability, the appetite for a given type of subject, the mobility, stays in their head or in a document only they will find again.
With bidirectional enrichment, the same sequence produces a living profile. Ahead of the interview, the Hub read the role and the candidate's history from the ATS, then it structures what is said during the exchange, and it writes back into the ATS a clean candidate profile, with its criteria filled in, a reasoned evaluation, and reusable context. Six months later, when a similar assignment opens, this candidate becomes findable again, because the information now exists in a searchable form and no longer only in a recruiter's memory.
It is this shift that answers the three pains we hear most often: tools that do not talk to each other, a volume of interviews hard to absorb when you recruit at the pace of an IT services firm or a recruitment agency, and a historical talent pool never reused. Data stops being a by-product of the interview and becomes an asset of the talent pool.
On top of this enriched profile comes the usage that makes the Hub tangible day to day: querying the base in natural language, the way you would write to a colleague. "Find me the SOC profiles we met this year, available and open to two days on site." You write a sentence where you used to assemble rigid filters, and the answer draws on the interview data that the write flow brought back up.
Why connect rather than replace
Three reasons, and none of them is ideological.
The first is risk. Changing your ATS means a migration, a data reload, change management, and recruiter buy-in that is never guaranteed. Many equipped companies know it: having an ATS improves profitability for two companies out of three according to the Cegid 2025 barometer, but only one in three says it is genuinely satisfied with its tool. That gap is not closed by buying one more tool, it is closed by finally making the most of the one already in place.
The second is complementarity. The boundaries between ATS, candidate CRM, sourcing tools, and HRIS are already blurring, and the role of a Hub is not to compete with your ATS connector on its own ground. It lives in the gap these tools leave empty: interview data, unstructured, that neither the ATS nor the CRM knows how to capture. Positioning the Hub as a partner to your ATS rather than a rival is the only coherent stance, and it is the one we hold.
The third is governance. Placing a layer on top of the existing setup lets you handle the question of data and compliance in one place, instead of scattering it. This is a sensitive point today, because most HR teams already run AI, but outside their business software: according to the myRHline 2026 barometer, 62.8 percent of HR professionals use AI through external tools like ChatGPT or Copilot, and only 5.1 percent directly inside their HR software. That means candidate data passes through consumer tools, with no framework. A layer of intelligence hosted in France, with no percentage scoring and where every evaluation stays explainable, answers this drift, a subject we develop in our article on the AI Act and recruitment and on our trust and security page.
This reasoning holds for a recruitment agency whose CV has direct commercial value, for an IT services firm absorbing large qualification volumes, as much as for an accounting firm that must validate a precise professional vocabulary. In all three cases, the ATS stays in place and gains a layer that finally makes it usable.
Frequently asked questions
Does an ATS-connected HR Hub replace my ATS?
No. The Hub sits on top of your ATS, which stays the system of record for the candidate profile, the status, and the pipeline. The Hub reads from the ATS and writes an enriched profile back into it, with no migration and no data reload. You do not change tools, you add a layer of usage and intelligence on the one your recruiters already know.
What is the difference between a read flow and a bidirectional flow?
A read flow lets the Hub consult the ATS data (profile, job, history) without modifying anything. A bidirectional flow adds writing: what the Hub produces during the interview, such as the structured summary and the evaluation, flows back into the candidate profile in the ATS. The bidirectional mode avoids double entry and makes interview data enrich your system of record instead of staying isolated.
Do you need to change your ATS to make use of your talent pool?
No, and it is actually the opposite. The talent pool rarely lies dormant for lack of an ATS, but because interview data is neither structured nor connected to the other sources. A Hub that plugs into the existing ATS structures that data and makes it searchable, which reactivates the talent pool without touching the pipeline in place.
Does the Hub work with any ATS?
The principle of a connected Hub is to adapt to your ATS connector through dedicated integrations. The read, write, and synchronization logic is the same whatever the system of record is; what changes is the connector. The best way to check compatibility with your setup is to talk it through during a demo.
Key takeaways
- An ATS-connected HR Hub does not replace your ATS: it sits on top and makes usable a set of data the pipeline already stores without reactivating it.
- The ATS stays the system of record, the Hub is the system of usage and intelligence placed on top, following the classic distinction between system of record and system of engagement.
- Three flows to distinguish: read (the Hub consults the ATS), write (it writes the summary back), bidirectional (both in sync, where the technical difficulty concentrates).
- Bidirectional enrichment turns every interview into a reusable candidate profile, which reactivates the talent pool instead of starting from zero on every role.
- Connecting rather than replacing reduces migration risk, respects complementarity with your ATS, and handles compliance in one place, in France.