TeamCity jobs' execution time vary a lot

Hi! The factors include:

• Agent (builds are run on different agents whose specs may also be different, the agent may or may not have dependencies required for the build cached locally);
• Revision of code (even when running the build on the same agent, building different revisions will not necessarily take the same time);
• Any environmental processes such as running backups, network congestion, and so on.

You can use the Compare Builds feature to check the differences in build agents, code revisions, parameters, etc.

Additionally, inspecting the full build log (Build Log page > Download log > select Full build log) will help identify the exact stages that took longer in one build than in another. Knowing what those stages are may be useful in pinpointing the root cause.