I am Priidik "Freddy" Vilumaa, an operations researcher and software developer interested in improving businesses through optimization methods. My expertise lies in mathematical optimization (constraint programming, MIP, metaheuristics, etc.), software development (Python, Java, JavaScript, SQL), and data analysis with a strong focus on supply chains (CV).

I completed my Master's degree in Technical University of Munich focusing on operations research for supply chains and software engineering. I spent the second half of my studies in Georgia Tech in Atlanta, where I took some OR classes but mostly worked on various industry projects with big firms such as Daimler and UPS. At the Physical Internet Center , my work focused on solving real-world logistics problems by applying new concepts and advanced analytics. I consider myself fortunate since I could work with very smart people on world's most interesting problems.

The past 5 years I've worked on various optimization projects. The bulk of this time I was using constraint programming to build planograms (shelf layouts) for retail stores. Shelf layouts can have a significant factor in store sales and this is one of the optimization problems that is still solved by hand to this day. Aside from generating planograms, I've worked on simulating and optimizing scheduled taxi services, fitting designs on industrial printing, routing school buses and more.

I built this site as an online portfolio to showcase the algorithms I create and their applications in the real world. Optimization has the power to make businesses, and the world, more efficient, and I hope to contribute to that mission. If you come across any bugs or have suggestions, feel free to reach out.

Contact: vilumaa [at] gmail.com |

Recent updates

April, 2025 - Added electricity demand management optimization, a model I had built for investigation of heating costs during the winter
November, 2024 - I start working on building the Estonian e-state through a company called Srini
November, 2024 - We move in and start fixing up yet another apartment
May, 2024 - A 20-strong group of people from our rowing club went to Brussels to run the 20km race. I finished just under 1:40:00, with a few seconds to spare
January, 2024 - I was honored to receive a small award from the Estonian Rowing Federation in recognition of my dedication in organizing the rowing championships
November, 2023 - Me and my awesome girlfriend started working on another apartment
October, 2023 - The Norwegian rowing legend Olaf Tufte came to Tallinn to give a talk to Estonian rowers
August, 2023 - Every summer I help the local rowing club, by building the course for Estonian National Championship. Got a nice timelapse
March, 2023 - I visit the Omnistream office, now moved to Sydney, Australia
February, 2023 - I get a green light on starting work on a new problem - an absolutely beautiful one - macrospace planning in stores. I.e. given shelf locations, in which region of the store should milk or bread, or fruit be. Mathematically viewed, it's a bilevel programming problem - the master (store) decides where the categories are located, the slave (customer) solves a routing problem. The objective of the master is to come up with a layout that maximizes impulse purchases for the slave
October, 2022 - While on a call with my manager, I come up with what I call a value curve approach. Essentially a set of diminishing curves (gain in y decreases as x increases), that when x is optimized give a good value of y. Combine with nonlinear curves (like step functions) and you have a pretty good approximation for many problems, say 2D planograms
August, 2022 - I start working on the "freezer planogram" problem, a 2D version of the shelf model
June, 2022 - A CP model rewrite using more integers and fewer booleans cut our average algorithm runtime by 50% and gave a 2% increase in objective value
May, 2022 - As a member of the Estonian Defence Forces army reserve, I take part in a huge army exercise lasting 2 weeks
April, 2022 - I visit the Omnistream office in Singapore
September, 2021 - I joined Omnistream, a Singapore-based startup that uses mathematical optimization to design planograms for retail stores
September, 2021 - I was contracted to mentor a team to work on a school bus routing software project
June, 2021 - I began working with a Washington, D.C.-based firm to assign seats for coworking spaces using constraint programming
March, 2021 - I started to renovate my grandfather's apartment and filming some timelapse videos for fun
November, 2020 - Started a project with a Dubai-based mobility company to investigate luxury scheduled taxi services using simulation and optimization methods
October, 2020 - Started working with an Irish printing company to optimize print sheet layouts
September 2020 - I joined yet another optimization competition
June 2020 - I released a video of 3PL style fleet and its routing here
March 2020 - I uploaded the first working examples on the Optimizer page
February 2020 - I received my diploma and am now officially graduated from TUM
December 2019 - Atlanta Estonian Cultural Society celebrated Christmas according to our traditions
December 2019 - We joined a Kaggle optimization competition
December 2019 - The first ♠Spades bot strategies are working
November 2019 - We started building an AI to play ♠Spades
November 2019 - I handed in my Master's thesis
August 2019 - Extended my stay in Georgia Tech for another 4 months
August 2019 - Commemoration of 30 years of "The Baltic Way" in Atlanta, the historic event that took place in 1989 in Estonia, Latvia and Lithuania, when 2 million people formed a 600 miles human chain, in a drive to gain independence from the USSR.
May 2019 - Started writing my thesis on route selection and containerization decisions in the Physical Internet