When I interview people, part of my observations include whether they can be understood, and whether they can understand me. After all, a huge part of working with someone, anyone, is communication; if you can't communicate with a person, you and that person are not going to be able to work effectively together.
We've all had to deal with programmers who came to our teams from foreign lands where languages other than our own are spoken. With some effort, one can learn to understand these folks, even through their sometimes heavy accents. However, it is required that they can understand and communicate in the language that we speak.
Sean X. is a developer who hails from Elbonia. After a short career in mud-farming, he tunneled out and escaped to America. He learned to speak English (or at least the American dialect thereof). He does so with only a minimal accent, and is easily understood. Sean also learned to be a top notch software engineer: he plans ahead, takes performance into account, as well as limiting and oddball circumstances, and he attempts to handle errors gracefully. You'd never know it today, but Sean still cherishes his Elbonian roots.
Sean recently interviewed a candidate for a mid level developer position. He began... "So, tell me a little bit about yourself."
The candidate was obviously nervous and self conscious, and hesitated to respond. Sean tried to ease the tension by giving the guy a chance to answer an easy question: "What is your background in software development?" The guy continued to fidget: "Me developer. Writer of code. Work in mud."
Somewhat perplexed, Sean continued: "This is a mid level developer position. What types of projects have you done that might qualify you for this position?" The candidate was clearly uncomfortable, and attempted to answer: "I... I... $*#%&!"
Somewhat floored, Sean recognized a damning expletive - in ELBONIAN! Sean, being a really nice guy, started speaking in Elbonian to put the guy at ease, and conducted the rest of the interview in their native Elbonian tongue.
The candidate nailed the interview and passed the technical and "likability" tests with flying colors. Sean recommended him for hire.
Normally, several folks would interview any given candidate, but due to folks being on vacation, out sick, and two family emergencies, nobody else was available. There was a political sense of urgency to fill the position so the usual multiple interviews were skipped and since Sean was well regarded, based solely on Sean's recommendation, the person was hired.
On the candidates' first day, Sean happened to be out sick. The guy showed up and started speaking in Elbonian. Of course, nobody on the team spoke Elbonian, so he was asked to speak in English. He proffered a piece of paper with a scrawled note: "I speak minimum English."
After 30 minutes of attempting to communicate with this guy, it was painfully obvious that he could not communicate with anyone on the team (except Sean). He was also unable to explain what a simple piece of code did because he couldn't understand English variable names such as "productCache" or function names like "addProductToCache". Yes, he could program in the language used on the project, but he would create variable and method names using the transliteration of Elbonian words. This was not going to work, so it was bucked to HR.
"But the guy has already been hired and he quit his job; we can't just pull the job offer at this point!"
"So what can be done? He will be of no use if he can't take directions or respond in normal conversation, let alone in technical discussions, or worse, debugging production problems. And if the code he writes is as incomprehensible as is Elbonian (to everyone else on the team), nobody except him and Sean will be able to understand it, let alone work on it - a potential critical point of failure."
The poor guy was made to sit at a desk and stare at the wall for his whole first day. Perhaps it was an improvement over mud farming, but still...
The next day, Sean returned to a wall of evil piercing stares and a flood of angry sounding emails from HR and upper management, and was ordered into a conference room - NOW!
After long and painful meetings with HR and management, the guy was put on another team where about half of the folks on the team spoke Elbonian, reasoning that half the team would never all be out at the same time.
HR would not create a formal policy - apparently because it might be construed as discrimination. So there is now an informal policy on the team that all interviews must conducted in English, and the person must be able to effectively communicate - in English.