Migration from legacy javascript to react in a well existing project isn't instant or easy, but the outcome will be worth it. How we can combine legacy with a modern front end, surviving the hybrid umbrella, improving application's client and enjoy coding ! The migration process from legacy javascript to react might take you some time and wouldn’t be easy, but the outcome will be worth it. Two years ago, the foreman project decided to adopt react and started a gradual migration process from legacy javascript (rails assets pipeline) into a modern react web app. We’d like to share with you our journey, the do’s and don’ts Why we should adopt react, Where to begin - The first step, How to survive under the hybrid umbrella, Gradual process - is it good enough? Long term goals (does SPA one of them?)