Boston software developer here, with a similar amount of experience as your husband. The market is hot here (as evidenced by my recruiter email folder), so you will probably have little trouble finding jobs. My general impression is that the majority of the jobs are concentrated in Cambridge / Boston, but with plenty in the surrounding suburbs. I used a recruiter for my last job search and found them helpful for finding companies in my target location that I might otherwise not have found.
The suburban office parks are not dying out. Some people do a "reverse commute" to the suburbs by transit or bike. For example, Burlington via
Bus 350 from Alewife; Lexington/Bedford via the
Minuteman Commuter Bikeway; Waltham via commuter rail or bus. Personally, I've previously done both a suburb-to-suburb (via car or bike) and a commuter rail commute from a suburb to Downtown. If I were to leave my comfortable suburban home and remote job and work in "Boston", I'd probably move to Somerville or Medford and commute by bike to Cambridge, or move to Jamaica Plain and commute by Orange Line or bike to Downtown/Fort Point.
To find apartments within commuting range (transit, walk, bike, etc), use
Walk Score Apartments.
Happy to answer any more questions (including via PM).