Applied December 2014, received a letter few weeks later, called in January to arrange interview for February.
There were about 20-25 of us in the room. Don't worry about other candidates as most people are nice and normal graduates just like yourself. Nobody was intimidating or that impressive.
Format was as follows:
Introduction from a Director, all about Aldi. Nothing to do here but listen.
First 2 minute presentation: Basically why you, why Aldi, what's your local store & an 'amazing' fact about yourself. Don't worry about going over time because a lot of people did (some for 4-5 minutes). In fact, plan a 4-5 minute presentation because this is basically your only chance to sell yourself - milk it. Focus on your relevant experience i.e. leadership roles, teamwork, evidence you're a hard worker who goes above and beyond. The people who stood out the most here said things like 'I'm the type of person who would be determined to make my stores the best no matter what.' It sounds obvious but not many people said it, and it seems like that's what they're looking for. When talking about Aldi, talk about the opportunities provided by the role - people management experience, why it appeals to you as a highly motivated individual etc. Maybe drop in some research on Aldi to show your awareness but don't go overboard - Aldi don't need to be told how great they are, and reeling off stats about their recent performance or amazing business model is a waste of time in my opinion. That said, it's probably worth mentioning something in that vein to illustrate you understand the Aldi culture etc. Definitely visit a local store as the Director specifically asked about this. The 'amazing' fact is a tricky one - some people's were light-hearted and this clearly didn't go down well. The best ones were along the lines of 'I raised x for charity', 'I cycled from x to y', or 'I captained/ran/organised XYZ event/club/sport at university'. Do your best to make it impressive as it's a chance to show off; if yours is average, you won't look great.
Following this was another talk from the Director, about the role etc. Then we had 5 minutes to prepare for the second presentation, on 'Your Greatest Achievement'.
Second presentation: This was strictly time constrained. 2 minutes goes by pretty quickly when you're talking so try and cover a lot of ground in a concise way for this one. The best ones were similar to the amazing facts - an impressive charity event, volunteering abroad, studying abroad, some kind of leadership role at uni etc. If you don't have anything exceptional to talk about, prepare the best thing you can and polish it up as much as possible. Emphasise why you were so successful doing this and what you achieved.
Verbal/Comprehension/Numerical test: All pretty basic. Verbal was word meaning questions along the lines of 'If angst is to fear, then joy is to ?'. Comprehension was 'John, Tim, and Julie like apples. Katy and Simon like oranges and apples. Kevin, Patricia and Georgia like apples and kiwi fruit, but not oranges. Who can eat apples and kiwi fruit? Who doesn't eat oranges?' If you haven't done maths since GCSE, practice for the numerical. It's a variety of fairly simple add/subtract/multiply/divide, with some percentages, fractions and decimals. Not complicated (60% of 300, 5.5-2.4, calculating change due). There were also some number patterns to work out. None of it is complex but if your maths is rusty it's worth practicing so you don't panic under pressure.
Overall it was an average/poor experience. Any interview is worth taking for the experience of being under pressure, selling yourself and presenting in front of large groups, so from that perspective it was worthwhile. However, as an assessment it was poor. Some people had travelled considerable distances and having only 4 minutes to sell yourself in a room full of 20+ candidates is frustrating. I'm an extroverted and confident person and I found it difficult to stand out. Though nobody was particularly impressive, those that did best were those who emphasised their passion to succeed and work hard etc - if that sounds difficult to articulate, that's because it is. There was no opportunity to display your personality or sell yourself beyond the contrived and formulaic group presentations. Some group tasks would have made this a more balanced and substantial assessment. If you do face an assessment like mine, above all try and convince them that this is your dream job, you are passionate about the opportunity to join Aldi's culture, you love leading and working with people, and will work as hard as humanly possible to make your stores exceed their targets.
To succeed at this stage you need to convey that you genuinely want the job, believe you'd be exceptional at it, and that you're passionate about the Aldi culture.
Hope this helps & good luck!