resume agent doubled the candidate's years of experience - overlapping contract roles got summed instead of merged

TL;DR: Compute total years of experience as the union of employment date intervals, not the sum. Two overlapping one-year contracts are one year of experience, not two. After the fix, the total matches what a human reads off the timeline.

resume agent doubled the candidate's years of experience  -  overlapping contract roles got summed instead of merged

1. Pull the parsed work history with start and end dates for each role. Expected: at least two roles with overlapping date ranges, usually contract or consulting stints.
2. Compute the naive sum and the union manually for one candidate. Expected: the sum is larger than the union, and the union matches the actual calendar span of the career.
3. Change the calculation: merge overlapping intervals first, then sum the merged spans. Normalize date formats first and treat "present" as the current date. Expected: the re-computed total equals the manual union.
4. Spot-check a candidate with one continuous job and no overlaps. Expected: the total is unchanged, so the fix only affects overlapping ranges.

Use this when

• A candidate's parsed years of experience exceed their actual career span
• The work history contains overlapping contract, consulting, or part-time roles
• Experience totals look roughly double what the resume timeline shows

Not for this skill when

• The roles are sequential with no overlap and the total is still wrong (that is a date-parsing bug, not a summation bug)
• The inflated number comes from counting freelance clients as separate jobs
• Date ranges are missing entirely

Variant phrasings

Resume agent summed overlapping jobs and inflated years of experience

Parser counted concurrent contracts as separate years

Candidate years of experience doubled by overlapping roles

Why it happens

Summing role durations is the obvious implementation, and it is correct for sequential jobs. Contractors and consultants routinely hold overlapping engagements, so a plain sum double-counts every overlapped month. Merging intervals before summing is the only calculation that matches calendar reality.

Edge cases

• Part-time roles held alongside full-time work: the union still counts overlapped time once, which matches how recruiters read it
• Open-ended roles with no end date: default to the current date, but flag the assumption in the record
• Date ranges given only as years ("2021 - 2022"): merge on year granularity and accept the coarser result rather than inventing months

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_FVcQsSNlnNfPSRtW7XSA