---
title: 'Founding Full Stack Engineer at Ajax'
canonical: 'https://feeny.ai/job/founding-full-stack-engineer-ajax-new-york-t6fszaap9hta'
type: 'job'
last_seen: '2026-09-09'
---

# Founding Full Stack Engineer at Ajax

- **Company:** Ajax
- **Location:** New York, NY
- **Employment:** full-time
- **Work type:** onsite
- **Posted:** 2026-02-18
- **Last confirmed live:** 2026-09-09
- **Apply:** https://jobs.ashbyhq.com/ajax/d7b2cd49-f068-488b-9b0d-ad87c71adc4d

## Job description

## OUR MISSION

Lawyers spend up to an hour per day tracking the work they’ve done, and fail to account for up to 20% of their work. Our goal is twofold:

1. Obviate the time tracking problem: track so accurately that interns could review the bills
2. Give law firms the management data they need to offer high-quality legal services at scale
3. Right now, law firms can’t undermine their pricing power by buying tech that speeds up the delivery of legal services. That sucks, and the data we collect lets firms figure out intelligent pricing strategies for the 21st century.

Metrics we’re proud of We’re solving the worst problem 1.5 million attorneys in the US face. Our metrics are exceptional:

- 14 customers have invested in Ajax with their own money
- <1% Customer Churn: we build long term partnerships with our customers (<10% annual is considered good) https://chatgpt.com/share/694c073e-9004-8001-9eeb-c0bc41bab23b
- 96% Pilot Conversion Rate: when we start pilots, we win them (>70% is considered good) https://chatgpt.com/share/694c0787-79b4-8001-8cb5-3074bd6a5f1c
- 140% Net Dollar Retention: after firms convert with Ajax, they share it with more and more employees (>120% is considered good) https://chatgpt.com/share/694c07ed-a0ac-8001-91c8-ed60e2f9da33

## WORKING AT AJAX

## HOW WE WORK, IN PRACTICE

Here’s a real sprint we had in November:

1. During a pilot with an important firm, the GTM team noticed that activation was low
2. We pulled some data from Posthog and Metabase and came up with a hypothesis: these users were the fastest billers we’ve ever seen, and Ajax’s entries weren’t ready for them in time
3. Nat restructured our React FE to show a Domino’s pizza style “entry in progress” tracker, assuring nervous billers that their work was indeed captured
4. Alex issued a native app update for our Flutter app that captured data more quickly when users task switch
5. Roger optimized some gnarly python async code to bring our p99 entry latency from ~180s to ~120s.
6. 🎉 We won the pilot! 🎉

## WHO YOU ARE

- Ownership: a wise man* once said the difference between senior engineers and junior engineers is that senior engineers own the feature into production and beyond
- Empathy: to build features end to end, you must be able to sit in our customers' shoes. Our company makes bs work go away for lawyers that work really hard; that needs to speak to you.
- Resourceful: you're scrappy: you prefer figuring bugs out yourself to putting your hands up.

*my coworker Andrew

## WHAT YOU’LL DO

- Prototype, test, and deploy new features like...
- What abstractions should our firm intelligence layer build atop the raw data ingestion?
- How can we go from processing 2TB (today) to 50TB (soon!) per day?
- Architect our existing 1TB/day pipeline to scale to 100TB
- Meaningfully contribute to team composition: every eng interviews every candidate

## YOU’LL EXCEL HERE IF

- Your reward function is customer happiness (stolen verbatim from our 2nd engineer).
- You want ownership - that means shipping your ideas and owning the results.
- You like adventure. We’re solving an unsolved problem, so we need to be brave and rigorous in our exploration. The optimal number of unsuccessful experiments is higher than 0.

I like working here because we win a lot, we’re solving previously-intractable technical challenges, and at least once a week a customer tells me that our product is saving their life. If that sounds fun to you, send me an email.

## FAQS

- How far along are we?
- We have 180 paying law firms and thousands of users
- Our team is 12 people (5 engineers, 7 Go To Market)
- We’ve raised $10mm in venture funding from excellent https://www.fika.vc/team VCs https://mxv.vc/
- Can I work remotely?
- We usually work 5 days/week in-person in FiDi, NYC. We’re flexible, though, and we get that people are adults - Tyler worked from home when he had some family staying over, and Nat took a Wednesday off recently because she had take delivery of a rare fish (don't ask).
- Compensation: $210-$270 base + .25%-.75% equity.
- The range is wide because we’re open to a range of seniorities.
- Offers may extend above but will not dip below the stated range.
- We also offer unlimited PTO, paid lunch/dinner on Fridays, and health/dental/vision.

[https://app.ashbyhq.com/api/images/user-content/8954a814-6357-4a8b-b368-455b52d3852c/e7c4ff65-2d74-4593-87d2-2c921db62a36/IMG_4300%20(1).jpg]

Roger slept through his alarm and joined standup

[https://app.ashbyhq.com/api/images/user-content/8954a814-6357-4a8b-b368-455b52d3852c/89f40bf7-4023-49b1-94db-d59bf64d6de4/IMG_8100%20(1).jpeg]

Innovation that excites from Brandon

[https://app.ashbyhq.com/api/images/user-content/8954a814-6357-4a8b-b368-455b52d3852c/0676f576-1dc6-42c2-a03d-9d0a7dd806c8/IMG_8061.jpeg]

Tyler can be a lot

## About Ajax

## Company Overview
- **One-liner**: Ajax uses AI to automatically capture lawyers’ activity across apps, documents, emails, and calls, generating polished, billable time entries to help law firms recover lost revenue and eliminate manual timekeeping.
- **Entity Type**: Private (funded startup)
- **Headquarters**: New York, New York, United States
- **Founded**: 2022 (sources vary; Tracxn lists 2023)
- **Founders**: Jack Weinberger (Co-Founder, GTM) and Alex Weinberger (Co-Founder, Product & Eng)

## Core Business
- **Primary industry**: Legal Technology / AI‑powered Productivity
- **Target customers**: Law firms of all sizes (B2B), from solo practitioners to large enterprises
- **Mission statement**: “Ajax captures everything you do across every app, document, email, and call. It writes detailed, OCG‑compliant time entries tailored to your voice, your matters, and your billing codes.” — [joinajax.com](https://joinajax.com/)

## Products & Services
- **Ajax AI Timekeeper** (SaaS): The core product. Continuously monitors a lawyer’s work across Word, PDF, email, browser, VoIP calls, calendar, Zoom/Teams, and other tools. Automatically drafts client‑ready, OCG‑compliant time entries, assigns matter codes, and learn from user edits. Syncs with billing systems via a single click.
- **Client Updates** (Feature): Generates draft client status updates based on recent work product, ready for review and send.
- **Email Filing** (Feature): Automatically matches emails to the correct matter and files them in the practice management system without manual drag‑and‑drop.
- **Integrations**: Compatible with SurePoint, Clio, MyCase, Filevine, PracticePanther, Centerbase, Actionstep, and most other billing systems.

## Market Standing
- **Valuation / Funding**: Not publicly disclosed. The company is funded (not bootstrapped), but the amount and round are not listed.
- **Key Metric**: Employee count is **9** per LinkedIn (with 44.4% YoY growth) — [linkedin.com/company/ajax-ai](https://www.linkedin.com/company/ajax-ai). A Tracxn report (May 2026) lists **39** employees — [tracxn.com](https://tracxn.com/d/companies/ajax/__2Y4mm3mqS69HNm6UeV7zsdUXfauzwmH_ekxyZxa5pVg). Revenue is not publicly available.
- **Notable Investors / Partners**: None publicly listed. Key product integrations include Clio, SurePoint, and MyCase.
- **Growth Signals**:
  - Claims **12% more billable hours** captured for firms using Ajax.
  - **95% of firms that pilot subscribe** (via [joinajax.com](https://joinajax.com/)).
  - Headcount grew **+44.4% YoY** (LinkedIn).
  - Engineering team is growing; job postings include Founding Full Stack Engineer, Design Engineer, etc.

## Competitive Advantages
- **Deep activity capture**: Unlike tools that only read calendar or email subject lines, Ajax sees the actual content of documents, research, and communications, enabling highly accurate, detailed entries.
- **Personalised AI**: The system learns from each user’s edits, adapting to their voice, billing preferences, and client requirements over time.
- **Security & Privacy**: SOC 2 certified, end‑to‑end encryption, configurable rolling data deletion, and a strict policy of never training AI models on customer data. Raw activity data is automatically purged.
- **High adoption rate**: The product is designed to fit naturally into a lawyer’s existing workflow (works in the background, one‑click sync), resulting in a 95% pilot‑to‑subscription rate.

## Strategic Focus
Ajax’s stated ambition is to become “the OS for the modern law firm” — [joinajax.com/careers](https://joinajax.com/careers). Near‑term priorities include:
- Expanding timekeeping automation to more billing systems and geographies.
- Building additional modules for client reporting, profitability management, and business development using aggregated Ajax data.
- Continuing to hire across engineering, sales, and customer activation to scale the product and go‑to‑market.

## Why Work Here
- **Tight, fast‑moving team**: Company size is ~9–39 people (discrepancy between sources), described as “the most customer‑obsessed startup in the world.” Employees have strong ownership and impact.
- **In‑person culture**: Roles are predominantly in‑office in New York City (some hybrid flexibility noted on BuiltIn).
- **Engineering‑first**: The founding team includes a former founding ML engineer (Roger Jin) and a PhD product engineer (Siyou Pei). Tech stack is modern, with emphasis on AI/ML.
- **Mission‑driven**: Removing the “worst part of a lawyer’s day” – a clear, emotionally resonant problem.
- **Perks**: Not explicitly listed, but small startup environment typically includes equity, early‑stage growth opportunities, and direct exposure to founders.

## Sources
1. [joinajax.com](https://joinajax.com/) — Product overview, features, integrations, results, security
2. [joinajax.com/careers](https://joinajax.com/careers) — Culture, team, job openings, mission
3. [builtin.com/company/ajax](https://builtin.com/company/ajax) — Perks, office details, year founded, jobs
4. [linkedin.com/company/ajax-ai](https://www.linkedin.com/company/ajax-ai) — Headcount, growth rate, executive list, locations
5. [tracxn.com](https://tracxn.com/d/companies/ajax/__2Y4mm3mqS69HNm6UeV7zsdUXfauzwmH_ekxyZxa5pVg) — Funding status, employee count (39), competitors

## Other roles at Ajax

- [Founding Account Manager](https://feeny.ai/job/founding-account-manager-ajax-new-york-c1zajwq0pemb) — New York, NY
- [Senior Product Designer](https://feeny.ai/job/senior-product-designer-ajax-new-york-q50egkavs5rq) — New York, NY
- [Founding Growth](https://feeny.ai/job/founding-growth-ajax-new-york-vyxfqghjrfkb) — New York, NY
- [Founding Account Executive](https://feeny.ai/job/founding-account-executive-ajax-new-york-xarp35agcrck) — New York, NY
- [Customer Activation](https://feeny.ai/job/customer-activation-ajax-new-york-8sftghhvv96x) — New York, NY
- [Founding Sales Development Representative](https://feeny.ai/job/founding-sales-development-representative-ajax-new-york-vk8nymksfjb7) — New York, NY
- [Founding Full Stack Engineer](https://feeny.ai/job/founding-full-stack-engineer-stand-new-york-9ns7t2xs98j7) — New York, NY
- [Founding Full Stack Engineer](https://feeny.ai/job/founding-full-stack-engineer-vamo-santa-monica-9wpea07jgtrw) — Santa Monica, CA
- [Founding Full Stack Engineer](https://feeny.ai/job/founding-full-stack-engineer-vantager-new-york-6dyk5z6hn1ps) — New York, NY
- [Founding Full Stack Engineer](https://feeny.ai/job/founding-full-stack-engineer-riley-san-francisco-78h1fysqs3tz) — San Francisco, CA