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SUBJECT /Maya Okonkwo
ROLE /Founder & CEO
BASED /Brooklyn, NY
VELLUM № 02 — THE INDEX
Climate Software Climate Software 2026 · Index 01 of 01

Building accounting infrastructure for the next generation of climate companies.

Founder & operator. Building Field Ledger — the general ledger climate-tech teams actually want. Twelve years inside high-growth startups, most recently as head of operations at three back-to-back Series-B teams.

NAMEMaya Okonkwo ROLEFounder & CEO ORGField Ledger, Inc. BASEDBrooklyn, NY EMAILmaya@fieldledger.co EST.2014 (operator) · 2024 (founder)
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An index of the subject.

Updated 26.04.26
001
$14M
Series A raised
002
42
Team members
003
3
Prior operating roles
004
12yrs
In climate & SaaS
002 / 005

Subject, in their own words.

~ 220 words

Maya is the founder of Field Ledger, a Series-A software company building the general ledger climate-tech operators actually want. She has spent twelve years inside high-growth startups, most recently as head of operations at three back-to-back Series-B teams.

She writes about the gap between climate ambition and operational reality, mentors founders out of Brooklyn, and serves on the board of two climate non-profits.

Before founding Field Ledger she ran finance and operations at Heron, scaled the early team at Watershed, and started her career on the investing side at Union Square Ventures.

At a glance

BornBrooklyn, NY
FieldClimate Software
StageSeries A
HiringEngineering · Sales
AvailableSpeaking · Advising
ReadingThe Hard Thing About Hard Things, 4th time
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What the subject works on.

06 areas
F-01Climate software & accounting infrastructure.
F-02Operational finance for early-stage companies.
F-03Hiring, onboarding, and leadership inside small teams.
F-04Board service at climate non-profits.
F-05Writing on the operating side of startups.
F-06Founder mentorship & angel investing.
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Recent shipping & writing.

2024 — 26
W-001

Field Ledger 1.0 — General ledger built around carbon as a unit.

A double-entry accounting system designed for companies whose books include tonnes of CO₂. Shipped in April; 14 paying teams in pilot.

Product · Field Ledger 04 / 2026
W-002

"The operating manual is the moat" — a long essay on second-stage scale.

Written for founders going from 20 → 80 people, on why the boring artefacts (handbook, RACI, finance close) are the actual product of leadership.

Essay · 7,800 words 11 / 2025
W-003

A talk at SHIFT'25 — "What climate tech can borrow from B2B SaaS."

A keynote in São Paulo on the dangers of fetishising mission and the underrated power of unit economics.

Talk · SHIFT'25 09 / 2025
W-004

Series A — led by Lowercarbon, with Sequoia & Lachy Groom.

Closed a $14M Series A to expand engineering and ship the multi-entity rollout for the back half of 2026.

Funding · Series A 06 / 2025
W-005

Board joins — Climate Founders Collective & Brooklyn Tech Foundation.

Two new board seats focused on accelerating second-generation founders and routing capital to Brooklyn-based climate companies.

Board · Non-profit 03 / 2025
W-006

"Why I left operating" — Field notes for founders #001.

A short post on the decision to step out of operating roles and start the company that was missing from the stack.

Essay · 1,600 words 01 / 2025
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Path.

2012 — 2026
2024 — Present

Founder & CEO, Field Ledger

Climate accounting software · Series A, $14M raised

Brooklyn, NY
2022 — 2024

Head of Operations, Heron

SMB lending platform · Series B

New York, NY
2020 — 2022

Head of Ops & Finance, Watershed

Carbon accounting · 0 → 90 people

San Francisco, CA
2018 — 2020

Director of Operations, Faire

Wholesale marketplace · Series A → B

San Francisco, CA
2015 — 2018

Investor, Union Square Ventures

Seed & Series A · Climate, fintech, infrastructure

New York, NY
2012 — 2015

MBA, MIT Sloan

Focus: System dynamics, sustainable business

Cambridge, MA
— / END

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