I've had several (previously) senior developers join projects I've led or worked on. It's really hard to get them up to speed and contributing effectively - som

I've had several (previously) senior developers join projects I've led or worked on. It's really hard to get them up to speed and contributing effectively - some never succeed :( Firstly, accept you're not going to be productive immediately as you don't have the project and business context. This is fine. Resist the urge to redesign everything, bring in new technologies and practices until you understand what is going on. Your instant reactions and conclusions will not be attuned to the needs of the project - so practice humility. Socially you may be used to knowing more than anybody else about the system you work on. Don't forget how much hard work this was to achieve the first time and get ready to do that again - but better :) Secondly, understanding you won't be contributing at a senior level to the project immediately, focus on learning the stack. One senior developer we had whose task was to do an integration of an open source program, got bogged down for months due to disliking the scripting language most of the backend was in. To learn a stack, make your own throwaway end-to-end projects. If you don't understand the stack, you won't contribute at a senior level. Thirdly, make sure to regularly commit code to the project. Of course, you have to talk to surrounding teams, customers, etc., and learn to cut releases, and so on, but most important is regularly contributing so as to get a feeling for who on the teams understands the system and what the real development process is like. Easy ways to make quick code changes beyond bugfixes: improve logging and metrics (also great for getting an overview of how things work). To support your suggestions for new practices and stacks: gather and document data about the real issues (regular causes of incidents, etc.) and build relationships. In time, the value of an experience transfer is huge - but the value of scattershot rewrites without context is hugely negative. Good luck!