Communications first occurred with a 30 minute phone screening to determine if I would be a good qualifying fit. From there, I was contacted with instructions to complete a programmatic challenge to be written in JavaScript that was estimated to take between 8 and 10 hours time as solved by current Facebook employees. The challenge, at it's core, was intended for candidates to prove their programming chops. Facebook was looking for both succinct and optimized solutions, i.e. you better use the most efficient algorithm available while still maintaining very few lines of code. The problem I was asked to solve looked fairly easy at face value, but I soon realized a few hours in that there were numerous edge cases that needed to be accounted for and would drastically reduce my algorithms efficiency due to nested loops. I solved the problem with a sub-optimal solution in around the time required but was denied continuation of the interview process. I wasn't given any real feedback, but I didn't ask for it either. The recruiter was very pleasant on the phone and in his emails.

Recruiter reached out on LinkedIn - kicked off with a quick 20 min screen. Basic stuff: past frontend work, JavaScript depth, and interest in Meta. First tech round was phone-based - focused on core JS (closures, async, array/object ops), and some quick CSS/HTML. Think clean, real-world problem-solving. Onsite had 3 rounds. Two were coding-heavy - writing functions in JS (e.g. flatten nested arrays, DOM builder from JSON, recursion). Not LC-hard, but structured thinking matters. Third was frontend system design - something like building a messaging UI or dashboard. They want to see how you architect, handle performance, and think through user interactions. Last round was a mix - light HTML/CSS coding plus behavioral stuff like debugging stories or past UI challenges. Prepped using Prepfully mocks (super helpful) + brushed up raw JS, DOM APIs, Big O, and UI-specific data structures. They care more about solid fundamentals and clean decisions than flashy tricks. Got the offer. Would say: know your tradeoffs, talk through your thought process, and don’t overcomplicate your code.