Reviewing Code Review : Defining and developing High-level ConceptualCode Review at a financial technology company

Abstract: Code review is a recurring activity at software companies where the source code, orparts of it, undergoes an inspection where the aim is to detect possible errors beforethe code is released for production. A variation of code review that is common today iscalled modern code review and is more lightweight practise than formal code review. Inmodern code review, the developers participate and continuously revise their colleagues’code.At a financial technology company in Stockholm, modern code review is applied. Thecompany has expressed a need to implement a tool that can facilitate the code reviewprocess. One suggestion from the company was to implement high-level conceptual codereview (HCCR), an idea of a tool where code changes are sorted automatically intodifferent commits with a specific message.In order to implement the tool, HCCR needs to be defined and concretised since it haspreviously existed solely as an idea. As a first step of the project, developers’ view ofwhat information is desirable in a commit needed to be examined. The project addressedthe following research questions: What information is desirable and needed by the developers of a medium-sizedcompany, to help them do code reviews in a pull-based environment?– What should the information consist of?– How should the information be presented?To answer these questions, interviews were conducted with software developers at thecompany, together with observations where the developers had to try out a first iterationof HCCR. The first iteration was developed using the company’s guidelines on howdevelopers contribute to code changes together with our company supervisor’s viewson how the tool can work. The interviews were recorded and transcribed, whereafteriia thematic analysis was applied. From the analysis, 13 concepts emerged, which weredivided into five categories. The developers wanted the commits to be atomic, compilableand testable in order to facilitate debugging. The developers also expressed a need toget clear information about both pull-requests (PRs) and commit messages. In theinterviews, a theme emerged that the messages should consist of: what has changed andwhy it has changed. Differences were also observed in the code review process as differentdevelopers use different strategies when reviewing code.Based on the information that emerged from the interviews and observations along withprevious research, a second iteration of HCCR was prepared. The report concludes bydiscussing possible implementations of the tool.