Sartori's Boston mandate telemetry across 26 closed Associate Recruiting searches records that 12 of those files targeted Corporate & M&A, life-sciences M&A or PE-corporate seats, and 9 of the 12 asked for class years 3–5 with SPA section ownership. Juniors (years 1–2) remain campus- and clerkship-led at lockstep platforms; pure junior laterals stay secondary when NALP reports direct-to-clerkship hiring up about 17% nationally in 2025. Mid-levels own the bandwidth market: diligence leadership, SPA schedules, disclosure schedules and buyer- or issuer-side workstreams already live on the desk.
Seniors and counsel-track lawyers (years 6–8) move when a partner build needs a second who can supervise two juniors and hold client calls on biotech strategic sales or PE add-ons. A hiring partner at a Boston Am Law Corporate & M&A desk told us a year-4 with two signed life-sciences SPA sections beats a year-5 with diligence-only history when the group is already mid-deal—and that ownership filter still loses to the conflicts grid if the biotech counterparty list overlaps. That ownership-plus-walls filter is the real shortlist gate, not school rank.
Supply is thin where Healthcare & Life Sciences M&A, PE-backed platform deals and pure strategic industrial M&A overlap. Platforms with meaningful Boston Corporate & M&A depth—Ropes & Gray, Goodwin, WilmerHale, Cooley, Mintz, Foley Hoag, Latham & Watkins, Kirkland & Ellis and peer national shops—set process norms. Expanding platforms such as Reed Smith's March 2026 Boston launch (12 lawyers from seven Am Law 50 firms, with PE, M&A and finance emphasis) hire against that benchmark when they need one portable mid-level, not another summer class of six.