News about Dyalog

Sep 4, 2023

Meet The 2023 APL Problem Solving Competition Winners


The 15th annual APL Problem Solving Competition winners were announced on 21 August 2023. Read about the experiences of the main prize winners and find out a bit more about them in their own words below.

Phase I of this year's contest had the familiar format of 10 one-line solutions, with 10 participation prizes being awarded to the submissions judged to make the best use of APL. Phase II was split into problem sets, with a single grand prize winner, second place, third place and non-student winner. The questions for each phase can be downloaded so that you can see what they tackled.


Andrea Piseri

The Grand Prize Winner is Andrea Piseri of Università degli Studi di Milano (University of Milan) in Italy. Andrea receives a cash prize of $2,500 USD and a delegate package registration for Dyalog '23 in Elsinore, Denmark.


"I discovered APL around 2022 from Conor Hoekstra's YouTube channel, which first got me interested in array programming and APL in particular, though I didn't understand it yet. I then decided to participate in Advent of Code using the language, which I used to learn about the primitives and syntax. I learned about the competition shortly after, through The Array Cast podcast and the APL farm.

"I've found quite a few interesting ideas while solving the problems, which I don't think would have come up if I had used a different language.

"The things I most appreciate about the language are its terseness and expressivity in dealing with collections of data, which gives it some advantage in mathematical applications, though I do think it is not as well suited for some everyday tasks."


Rory Kemp



The second place winner is Rory Kemp, who attends the University of Oxford in the UK. Rory receives a cash prize of $1,250 USD.


"I have been learning APL for a few years now, and this is my third time entering the APL contest. Every year the problems have been challenging and enjoyable, this year in particular. They are a great chance to practice programming in the array paradigm, which is unfamiliar coming from a more traditional CS background. It forces you to approach things differently, but the new patterns end up being applicative in "regular" languages as well. Learning APL has definitely made me a better programmer in general.

"As well as being powerful and useful, APL is also extremely fun, and I would highly recommend anyone APL-curious to try learning it. I'm sure I will keep using it for many years to come."


Dzintars Klušs




The third place winner is Dzintars Klušs who attends Rīgas Tehniskā Universitāte (Riga Technical University) in Latvia. Dzintars receives a cash prize of $750 USD.


"I found out about APL on a code golfing site, where it fit in quite well due to its terseness, but APL quickly turned out to be useful for much more than just golfing, becoming my go-to calculator and scripting language. Nowadays I'm using BQN and participate in its development."


Alexander Block



The Winning Professional Entrant is Alexander Block. Alexander receives a delegate package registration for Dyalog '23 in Elsinore, Denmark.


"I am 33 years old and I work as a life insurance actuary for Viridium, a German company specialising in management of life insurance portfolios. My original academic background is in mathematical logic, but I started to work with APL immediately after entering the insurance sector in 2017. I have taken part in the development of two calculation engines (written in APL) for testing the mathematical correctness of insurance benefits. Still, I have barely scratched the surface of the capabilities of idiomatic APL and, therefore, saw the APL Problem Solving Competition as a great opportunity to deepen my knowledge. I am generally passionate about functional programming and therefore mostly enjoy the functional aspects of APL, especially the wholemeal approach to operations on data structures, as well as its conciseness and conceptual clarity."


Andrea and Alexander will both be presenting their winning work at Dyalog '23 in October.

This is the 15th consecutive year that we – together with sponsors InvestCloud and SimCorp – have run the International APL Problem Solving Competition. We would like to thank the sponsors for making it possible to continue to run this annual programming challenge.

Register now to be notified when the next competition launches in spring 2023.

Congratulations to all the winners.