How to stay focussed?

Who is the enemy of a software engineer? What is it that (s)he needs to fight against to succeed?

I believe it is a distraction.

Unlike other industries such as construction where you are constrained by raw materials and tools, in the software industry, all libraries/tools are available mostly free, all it requires is the focused time to build anything. You mind space, time or focus is the only thing that matters. So, make sure you proactively cut down all distractions or anything that occupies your mind space.

Here are some of the things that work for me.

1. Use the Pomodoro technique of fixed working and break periods. Use this kind of app https://play.google.com/store/apps/details?id=com.AT.PomodoroTimer Don’t take a break or look into the phone notification whenever you are stuck. Instead, do it at fixed periods. Keep the phone and laptop’s notifications off.
2. Use a physical notebook to make notes and todos. Because if your computer isn’t working or is slow, you would get time to review your notes and todos instead of getting distracted.
3. Stop switching between tasks or projects. Do only one thing at a time and keep appending whatever is trying to take your focus to the todo list.
4. Think of yourselves as split personality: one is a planner who creates to-do list and the other one executes them. These two personalities should talk to each other by the way of writing.
5. Staying focused is a habit. It takes weeks to build a habit and it takes an hour to break it. Protect your focus fiercely.
6. External commitments. If you deem something is important and you want to achieve it, it is better to commit publicly about it so that you don’t postpone it and you would keep it at a higher priority.