For Series A B2B SaaS · Allston Labs

Outbound infrastructure for scaling B2B SaaS — past the founder, before the SDR org.

You have PMF signal. Repeat closed-wons in a definable ICP, $1-5M ARR, the first two-to-four AEs hired or hiring. The motion worked when the founder ran it. It is not yet a system, and the AE team is starting to feel it.

This is the awkward transition. The chapters below are the systemization layer.

The case

Most Series A B2B SaaS companies hit the same wall — the founder-led outbound that produced the first 30 logos depended on the founder's calendar, the founder's domain reputation, and the founder's reply discipline. The first AE inherits a sending stack nobody documented, a list-build process that lived in the founder's head, and a reply queue with no SLA. 60% of first-AE hires fail this way — not because the AE is wrong, but because there is no motion to hand them. The next two quarters either harden the upstream or watch the AE team hit a ceiling that has nothing to do with the AEs.

What to read first.

  1. 01
    Sales motion
    First AE transition — when, who, and the 90-day ramp

    60% of first-AE hires fail. Most are hired before there is a motion to run, or against a profile that needs polished collateral the company can't yet provide. When to hire (not before $500K-1.5M ARR), who to hire, and how to ramp them so they hit OTE in quarter two.

  2. 02
    Sales motion
    Multi-thread engagement — past the single champion

    Single-thread deals close at 8-15%. Multi-thread closes at 35-50% on the same pipeline. The per-role engagement architecture — champion, economic, technical, hidden veto — that your first AEs need from week one.

  3. 03
    Email infrastructure
    Cold email infrastructure — the complete reference

    Most Series A founders inherit a sending stack thrown together in the batch and never rebuilt. The 14-chapter audit of what should actually be in production now. Read the architecture and operations layers at minimum.

  4. 04
    Replies
    The four-hour triage window

    Reply handling is where 50% of pipeline gets left on the table. Five-minute response converts at 4x next-day. The routing discipline behind it. The reason your AEs' calendars are either full or empty.

  5. 05
    Replies
    Objection handling — four canonical stalls

    Per-objection response library that converts at 8-15% of objection replies, vs under 1% when treated as a no. The training material your first AEs should onboard on.

  6. 06
    ICP
    Segmentation architecture

    With 5-15 closed-wons, segmentation work begins. 3-7x per-segment reply rate differential when done correctly. The work that lets two AEs cover what one AE cannot.

  7. 07
    Copy
    Multi-channel orchestration

    Email + LinkedIn + phone, coordinated, not three siloed channels. 1.4-1.8x cumulative reply over single-channel. The orchestration that hides the channel complexity from the AE.

What we do for Series A B2B SaaS.

We run the upstream so your AEs run the sales motion.

Lists, sequencing, deliverability, reply routing, reporting — operated end-to-end by an engineer in your Slack. Your AEs spend their day on discovery, multi-thread, and close. They never touch a domain, an inbox, a list build, or a deliverability incident.

An audit before an engagement. Every time.

The first call is a free 30-minute review of your sending estate, sequence library, and reply discipline. We name the three highest-leverage fixes. If they are inside your team's bandwidth, you walk with the chapter references. If they are not, we scope an engagement.

Forward-deployed engineers, not a platform.

We are an engineering team. The infrastructure lives under your entity — your domains, your DNS, your accounts. The operator on call writes code. If your stack needs custom enrichment, custom routing, or a custom intent integration, we ship it the same week.

Case in production.

Series B SaaS · 4 AEs · 90 days

32 domains, 96 inboxes, zero burned in 90 days. Primary-tab placement above 98%.

B2B SaaS, Series B, four AEs, eight-figure ARR. They inherited a 12-domain sending estate from the batch era with two domains already blocklisted, no centralized warmup discipline, and a reply queue that ran from the head of sales' personal inbox. We rebuilt the estate from scratch — 32 domains across two TLDs, 96 sending inboxes, isolated subdomain architecture with the corporate root untouched — and ran a 28-day phased warmup before the AEs touched anything.

Seed-list testing across Gmail, Outlook, Yahoo, iCloud, and a representative Exchange tenant tracks 98%+ primary placement weekly. Reply routing into AE-specific Slack channels with a four-hour SLA. Zero domains burned across the 90 days.

AE-level result: meeting-booked rate from outbound up 2.4x against the prior quarter at the same sending volume. The AEs spent the quarter on discovery and multi-thread, not on debugging deliverability.

For founders hiring their first AEs

Free the AE calendar from infrastructure work.

Book a free 30-minute audit. We will look at your sending estate, sequence library, and reply discipline, and tell you the three highest-leverage fixes. If they are inside your team's bandwidth, you go execute. If they are not, we scope an engagement.

← Back to Library