My GSoC workflow

I have talked about the proposal, the blog, open source software, what my project is about, and some weeks have passed since the start of the coding period, however, now I realize I have yet to talk about what GSoC is and what is my daily routine as a participant. This post will have two main sections, one little introduction about GSoC (all the info about the program is available on its official site), and a second larger section on my daily work routine.


Google Summer of Code is a global program organized by Google Open Source. Its goal is at the same time to support students by giving them the opportunity to work as programmers during their summer and to empower and increase the open source software community. It started in 2005 with 200 students, growing every year and reaching 1276 accepted students in 2019.

GSoC has two selection phases, one for free open source projects and another for students. Once the organizations have been selected, it is up to the organizations alone to choose which students are accepted. Google’s role is to assign the number of student slots per organization, not who fills them. I have not been able to find much information about the slot assignment process, but it looks like it depends on the number of proposals received and the total number of students each organization is able to mentor. Afterwards, during the summer, students code for their OSS project, while getting paid by Google.

In order to make sure that both student and mentor are following the program guidelines, there are two 15 minute evaluations, were the student has to answer some questions abut the mentor and vice-versa. If passed, these evaluations trigger the payment of part of the GSoC stipend. Eventually, there is a final evaluation, were students must also write a summary of their work and links to the code produced.

My workflow

My work for ArviZ during GSoC covers a wide range of tasks that goes even further from all the tasks detailed in the proposal. Hence, organization and planning are vital in order to achieve my goals. Moreover, not only I have to plan all the different tasks and how to divide work but also when to do them.

For task management, GitHub itself already has plenty of features to help me organizing them. When I started coding, I would send a pull request (PR) to from my fork to ArviZ main repository as early as possible. Thus, my PR start generally labeled as WIP (Work In Progress) and grow and sum commits as time advances. I also include a description of the PR goals and some examples in the first PR message. This methodology allows all ArviZ contributors to know what the PR is about, and to advise and review early on in the coding process. In addition, all continuous integration test are run for most of the commits, making sure I am not breaking any of the other functions in ArviZ. In some cases, I also used checklists (which can be directly embedded in PR messages) to keep track of all features and subtasks pending in the PR. Eventually, if some related subtask goes beyond the PR, I would create an issue to keep track of these pending tasks.

For time management, I relied on time tracking software. It would allow to keep track of how much time I spent on each PR, and even inside each PR how the time was divided between reading literature on usage of the algorithms, coding itself and writing tests. Time management is really important for me, because I always want to fully understand what I am doing, which in some cases is great, but in some others it can slow me down a little bit; using time tracking made it clear to me when to move on to the next task in order to keep up with the planned timeline. Also, writing detailed descriptions of what I was doing, would make starting to work the next day even easier as I would know exactly where I left off.

Afterwards, when the PR reached its end point, before considering it ready for merging, I would also test the code in some realish examples, not only in the automated continuous integration tests. I already have a whole task in the proposal for testing on real examples, which is why these examples are quite simple and I label them as realish, not as real. In some weeks I do plan to get to the real case testing, which will be to check out some github repositories using ArviZ or any of the supported MCMC libraries and apply the stats and diagnostic functions on these real examples. Doing this I plan to achieve two goals. The first one and most important is to prove that all the algorithms work in all real cases, and the second goal, which is optional, is to create some PR on one of these repos, in order to extend knowledge and usage of the implemented algorithms.