After I apply to a few companies, I can easily reuse resumes with little to no modifications. The goal is to hit as many job requirements in the job description as I have experience for without overwhelming the recruiters and hiring manager with irrelevant information.
I only submit cover letters if they are required, or if I have a unique connection that I can bring up (e.g., having met the hiring manager at a recent meetup).
What if you dont have any JS experience, but have say several years working on .NET and Java. Removing that experience makes it looks like you're an entry level candidate, when in reality theres actually a decent amount of transferable skill between the tech in question and if you have enough informal experience with Node (through personal projects, etc.) you should have little issue switching.
Also, I should have been more clear. I don't erase everything about a past experience if it's a different technology. Here are a couple hypothetical examples to help clarify. In this first version of a resume snippet, the applicant should be applying for a Java position since it's filled with terms that make sense to the Java community:
> Software Enginer at XXX Company
> * I led the design and implementation of XXX Company's internal payment processing service which processes $YYY million USD in annual revenue. The project used Java, Spring, Hibernate, and MySQL.
> * Introduced testing (JUnit and Mockito) into the engineering culture by leading brown bag talks. Increased unit test coverage on critical company projects from 0% to 73% over 2 years.
> * Used JNI to integrate critical path code with XXX Company's proprietary hardware driver, increasing average performance by 8x.
Here is a snippet representing the same experience, but catered toward a Node.js position. References to enterprise Java are removed, and the last bullet is replaced with a more relevant bullet:
> Software Enginer at XXX Company
> * I led the design and implementation of XXX Company's internal payment processing service which processes $YYY million USD in annual revenue.
> * Introduced testing into the engineering culture by leading brown bag talks. Increased unit test coverage on critical company projects from 0% to 73% over 2 years.
> * During XXX Company's annual hackathon, I implemented and presented a functional prototype service to present payment information in real-time using WebSockets.
Now these changes alone are likely not sufficient to get a call back from the Node.js job position, but it changes the automatic typecast from "experienced Java developer" to "experienced developer" Hopefully this candidate has some other past experience in Node.js/web development/JavaScript to flush out the story.
I use to think that a well crafted custom cover letter totally gives me a leg up on the competition. But recently, I've been gettin lazy and not sending cover letters and I still get responses. Go figure.
The notion of a cover letter is pretty outdated for most jobs. The people still teaching their use are firmly rooted in the age of sending unsolicited job applications via mail that will be screened by a human.
(that's around the same level of Matt Cutts Current Job)
Edit: I meant to add that I am also happy to review your resume and provide feedback, too. Contact in profile.