---
title: 'Senior Backend Engineer at Junior AI'
canonical: 'https://feeny.ai/job/senior-backend-engineer-junior-ai-london-5s020y3dky2j'
type: 'job'
last_seen: '2026-09-07'
---

# Senior Backend Engineer at Junior AI

- **Company:** Junior AI
- **Location:** London, United Kingdom
- **Compensation:** £100k–£120k
- **Employment:** full-time
- **Work type:** onsite
- **Posted:** 2026-01-21
- **Last confirmed live:** 2026-09-07
- **Apply:** https://jobs.ashbyhq.com/junior/52a74883-a538-4621-b573-a8cf6467781f/application

**Skills:** PostgreSQL, Python, TypeScript, Snowflake, BigQuery, Databricks, Firebolt, Data Pipelines, API Development, LLM Integration, AI-enabled workflows, Automation systems, Internal developer platforms

> Design and scale backend systems for an AI-driven research platform, focusing on data pipelines, integrations, and automation. This high-ownership role involves building internal infrastructure and tools to support product, commercial, and operations teams in a fast-moving startup environment.

## Job description

## ABOUT JUNIOR

Junior is building the AI operating system for investment research. Our software helps private equity firms, consultants and financial institutions complete high-stakes research workflows dramatically faster - from diligence and memo writing to market mapping, research synthesis and strategic analysis.

We’re trusted by several of the world’s top private equity firms, Big Four consultancies and leading financial institutions.

- Bootstrapped and profitable
- ~£20M+ in revenue, after growing 10x last year
- 60+ people across the company
- 20-person engineering team, doubling to 40 this year
- Core stack: TypeScript, Next.js and PostgreSQL

You’d be joining early enough to shape the product, engineering culture and company, but with enough traction that everything you build lands immediately in front of demanding, paying customers.

## ROLE DESCRIPTION

You’ll build and scale the systems that power our AI-driven research products and enable our operations / sales teams to deliver our product as efficiently as possible. This is a systems-level role - ideal for engineers who love thinking about data flows, orchestration, and performance across complex distributed systems.

You’ll have the opportunity to:

- Ship quickly
- Architect and scale backend systems that support high-throughput LLM interactions, vector search, and multi-agent orchestration.
- Stitch together AI infrastructure across model providers, data stores, and internal APIs to create cohesive, performant systems.
- Prototype new backend capabilities (retrieval pipelines, caching layers, async task queues) that let us build faster and smarter
- Own the architecture of internal data systems and pipelines
- Build automation and integrations across product, CRM, and financial systems
- Help shape engineering culture and internal infrastructure decisions

## ABOUT YOU

We’re looking for a Backend Engineer who enjoys building systems that make a company run better.

You might be a good fit if you:

- Are based in London and excited to work from our Farringdon office (5 days/week)
- Have experience owning technical projects end-to-end, from architecture through production
- Are excited by the intersection of AI infrastructure, financial systems, and backend engineering
- Enjoy translating business problems into clean technical systems and automation
- Have worked with PostgreSQL and care about data modelling, reliability, and system design
- Write production code in Python, or TypeScript
- Are comfortable building APIs, internal tools, workflows, and infrastructure that support real customers
- Thrive in fast-moving startup environments and enjoy shipping quickly while maintaining strong engineering standards

Bonus points for experience working on:

- Billing, payments, usage-based pricing, or financial workflows
- Internal infrastructure / dev tools at startups
- Data pipelines, workflow orchestration, or event-driven systems
- Retrieval, embeddings, or prompt orchestration

## 🧭 INTERVIEW PROCESS

The process moves in days, not months:

1. Introductory call: background, motivation and mutual fit
2. Live technical screen (30-mins): solving a Python problem live in an IDE with one of our engineers. We optimize for speed and completeness over polish, and the interview is completed without AI tools
3. On-site Interview: a full afternoon of coding, a system-design whiteboard and a product discussion with one of our PMs
4. Final Cultural Round: a final conversation about how you work, what motivates you and whether Junior is the right environment for you
5. Offer: decisions are made collectively and quickly

🌵 WHY JUNIOR?

- Top 1% traction: 0-20+ m rev in 3 years, fully bootstrapped / profitable, top-tier customers inc. some of MBB, Big 4, Top 5 PE mega-funds
- Flat org structure: lean startup environment – every engineer reports directly to the CTO / co-founder
- Competitive salary + equity and first-class benefits, including:
- Team lunch provided everyday at the London HQ!
- Third Space membership
- Private health insurance
- Multiple all-expense paid offsites per year (last 3 trips include Crete, Greece; Cancun, Mexico; Barcelona, Spain)
- Visa sponsorship available

If you’re excited to drive innovation at Junior, we’d love to hear from you!

## About Junior AI

## Company Overview
- **One-liner**: Junior AI provides voice intelligence and AI-powered analysis for M&A teams, turning expert call transcripts into structured, searchable knowledge.
- **Entity Type**: Private (Seed stage, based on "seed to Series A" language on careers page)
- **Headquarters**: New York City, New York, USA
- **Founded**: 2023
- **Founders**: Not publicly disclosed

## Core Business
- Primary industry/industries: AI-powered software for investment research, M&A diligence, and private equity workflows
- Target customers: B2B – investment professionals, private equity firms, corporate development teams, investment banks, management consultants (MBB, Big 4, MegaCap PE Funds, global investment banks)
- Mission or purpose statement: "Using AI to streamline investment research" (from about page)

## Products & Services
- **Junior Platform**: Voice intelligence platform that records, transcribes, and analyzes expert calls, diligence interviews, and pipeline discussions. Includes:
  - Best-in-class transcription with structured extraction of expert call insights
  - Instant key takeaways automatically generated after each call
  - Intelligent search across transcripts to pinpoint relevant insights
  - Quantitative tracking to monitor findings across interviews
  - Custom GPT-based synthesis for querying and summarizing expert input
- **Alexandria**: A custom conversational library that centralizes all notes, searchable by deal, sector, or attendees.
- **Compliance Tools**: Real-time compliance oversight, programmatic MNPI detection, zero data retention agreements with underlying model providers, data retention controls, secure data hosting.
- **Integrations**: Calendar (Outlook/Gmail), recording bot for Zoom/Teams/GMeet/Webex, direct pipelines from leading expert networks, APIs for data export.

## Market Standing
- **Valuation/Market Cap**: Not publicly available
- **Key Metric**: 30% month-over-month growth (from careers page); "trusted by thousands of consultants, investors, and bankers"
- **Notable Investors/Partners**: Not publicly disclosed
- **Growth Signals**:
  - 30% MoM growth
  - 24 team members (per careers page; Built In lists 111 total employees – conflicting reports, likely reflecting different timeframes)
  - "Seed to Series A" trajectory over 18 months
  - Expanding product features (e.g., "Every data source" coming soon)

## Competitive Advantages
- **AI-native for M&A**: Custom NER engine trained on deal workflows, recognizing entities that matter to investors and advisors.
- **Enterprise-grade compliance**: Programmatic MNPI detection, zero data retention with model providers, GDPR-aligned controls, secure hosting on Junior’s infrastructure.
- **Deep integration**: Direct pipelines from leading expert networks, calendar and meeting platform bots, APIs for data warehouse connectivity.
- **Speed and focus**: Small team, weekly deployments, fast iteration – "Speed is our competitive advantage."

## Strategic Focus
- Building the "AI brain for M&A" – turning messy transcripts into actionable intelligence
- Expanding data ingestion methods and source connectivity (recording bot, expert networks, file uploads, manual notes)
- Scaling from seed to Series A while maintaining velocity and customer obsession
- Institutional knowledge capture – reducing rework and increasing IP value

## Why Work Here
- **Culture**: "Small team, big ownership" – end-to-end ownership from conception to deployment; ship meaningful work immediately
- **Values**: Ship Fast, Show Your Work, Open by Default, Customer First, Velocity over Perfection, Meritocracy, Radically Transparent, Own It
- **Work environment**: In-office at NYC headquarters (HQ in New York, all jobs listed as "In-Office" on Built In)
- **Engineering culture**: Weekly deployments, "fix fast", AI-native tech stack, direct customer interaction
- **Perks**: Not explicitly listed, but emphasis on solving real problems, no politics, visible roadmaps and metrics
- **Growth**: 30% MoM growth, seed-stage startup with clear product-market fit, opportunity to shape the company

## Sources
1. [junior.ai](https://junior.ai/)
2. [junior.ai/about](https://junior.ai/about)
3. [junior.ai/careers](https://junior.ai/careers)
4. [jobs.ashbyhq.com/junior](https://jobs.ashbyhq.com/junior)
5. [builtin.com/company/junior](https://builtin.com/company/junior)

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