EPSO AD5 vs AST vs CAST: Which Competition Actually Fits You Best?

A lot of people start looking into EU careers and immediately get confused by three terms that appear everywhere: AD, AST, and CAST.

At first, they sound almost identical. They all involve EPSO-style testing, EU institutions, and competitive applications. But once candidates begin researching more seriously, they quickly realise these competitions lead to very different types of roles and responsibilities.

Some people apply for AD because it sounds more prestigious, while others completely overlook CAST opportunities without understanding how flexible they can be.

So before starting your preparation, it helps to understand one simple thing first: what kind of role are you actually looking for?

AD Competitions — Policy, Analysis, and Decision-Making

AD stands for Administrator, and these competitions are usually aimed at university graduates.

AD roles are often connected to:

• policy development
• EU legislation
• economics
• law
• project management
• administration

The most popular entry-level competition is AD5.

Many candidates are attracted to AD roles because the work is more analytical and decision-oriented. Depending on the institution, employees may contribute to reports, negotiations, policy discussions, or projects connected to EU decision-making.

At the same time, AD competitions are highly competitive and require strong reasoning performance under time pressure.

More about AD competitions:
→ https://euknowledge.eu/ad-epso-exams/

AST Competitions — Operational and Support-Focused Roles

AST stands for Assistant.

These positions are usually more practical and operational compared to AD roles.

AST staff often work in areas such as:

• HR
• finance
• communication support
• administration
• coordination tasks

A common misconception is that AST roles are somehow “less important,” but EU institutions rely heavily on operational staff to function efficiently every day.

For many candidates, AST positions are attractive because they combine structured responsibilities with long-term career stability.

More about AST competitions:
→ https://euknowledge.eu/ast-epso-exams/

CAST Competitions — Flexible Opportunities Across EU Institutions

CAST stands for Contract Agents Selection Tool.

Unlike AD and AST competitions, CAST is mainly used for recruiting contract agents for temporary or flexible positions across different EU institutions and agencies.

These roles can vary a lot depending on the department. Some are administrative, while others may involve communication, finance, project support, or IT-related work.

One reason candidates underestimate CAST is because the process feels more flexible and ongoing. Many assume they can simply prepare later if they are contacted — but institutions can move quickly, and candidates may suddenly need to switch into exam mode with very little notice.

More about CAST:
→ https://euknowledge.eu/cast-epso-exams/

Which EPSO Competition Is Harder?

There is no single answer to this question.

The difficulty often depends more on your strengths, work style, and preparation than on the competition itself.

Some candidates feel more comfortable with analytical policy work, while others prefer structured operational roles or more flexible opportunities through CAST.

What all three competitions have in common is pressure.

Most EPSO exams include reasoning-based computer tests such as:

• verbal reasoning
• numerical reasoning
• abstract reasoning

And for many candidates, the real challenge is not the knowledge itself – it’s maintaining focus, accuracy, and timing under pressure.

How EU Knowledge Supports EPSO Preparation

The EU Knowledge team designed its AD, AST, and CAST preparation courses to help candidates feel more prepared for the real pace and pressure of EPSO competitions. Through realistic simulations, reasoning practice, and structured preparation packs, candidates can gradually become more familiar with the exam environment and improve weaker areas more effectively. The goal is not only to practice questions, but also to build confidence and consistency before exam day arrives.

Your EPSO Journey Starts With Preparation

There’s no perfect choice between AD, AST, and CAST – only the path that fits your strengths and goals best.

And in most EPSO competitions, confidence usually comes from one thing more than anything else: consistent practice before the real pressure begins.