---
title: 'Senior Customer Success Engineer - API at Duffel'
canonical: 'https://feeny.ai/job/senior-customer-success-engineer-api-duffel-london-hhtwep1gxxjd'
type: 'job'
last_seen: '2026-10-16'
---

# Senior Customer Success Engineer - API at Duffel

- **Company:** Duffel
- **Location:** London, United Kingdom
- **Employment:** full-time
- **Posted:** 2026-03-05
- **Last confirmed live:** 2026-10-16
- **Apply:** https://jobs.ashbyhq.com/duffel/f39d2b59-d071-4bd7-8185-81fb8ef7d249/application

**Skills:** RESTful APIs, API Integration, Debugging, Scripting, SQL, Programming Languages, Data Analysis, Travel Technology, Airline Distribution Systems, Hotel Distribution Systems

> Provide expert technical support and API integration guidance to large enterprise customers. Collaborate with cross-functional teams to resolve issues, drive product adoption, and optimize customer performance using Duffel's API tools.

## Job description

We are making travel effortless. Join us.

Whether it’s to visit the people closest to us, starting an exciting adventure, or a career-defining business trip, travel is an essential part of our lives. Yet we've all experienced the aches and pains of getting to our destination. Today, more than 4 billion airline passengers rely on technology that hasn't kept up with the expectations of the modern connected traveller.

That’s why we’ve started to rebuild the infrastructure that underpins the travel industry. We’re on a mission to unravel travel — simplifying systems and building the tools that will make the future of travel effortless.

We were part of Y Combinator S18's cohort and we are backed by Benchmark, Blossom, Index Ventures and Kima Ventures. A fantastic set of investors that has helped build some of the world's largest companies.

## Overview

If you have a passion for helping customers and solving challenging technical problems then this may be the role for you. Duffel is hiring a Customer Success Engineer (CSE) to provide expert technical support to our largest and most important customers. You will help our customers by addressing their current questions and suggesting ways to use our APIs to build the best travel experience for their users. Additionally, you will collaborate with a cross-functional group across Duffel including Product, Engineering, Finance, and Travel Operations to ensure a superior customer experience with both the product and the company as a whole.

## What we're looking for in you

- Bachelor’s degree in Data Science, Business Analytics, Statistics, Computer Science, or a related technical field.
- 5+ years in tech support helping enterprise customers use a RESTful API product
- Experience integrating APIs, debugging integration issues, writing scripts and SQL queries.
- Ability to read (and ideally write) code in multiple programming languages
- Track record of expeditiously answering and solving product related questions
- Eager to embrace the culture and objectives of a fast moving startup
- Able to handle diverse responsibilities and work independently to achieve desired results; have sound judgment and business acumen.
- Excellent communication skills with ability to express complex business and technology issues in a clear way.
- Operational mindset: you’re eager to build processes for yourself and the team to maximise productivity.
- Strong analytical skills: you enjoy digging into data to find insights and drive decisions
- Experience working in cross-functional teams and continuously delivering feedback to shape product roadmap and influence sales strategy
- Track record of engaging effectively with customer staff of all career levels
- A plus: Knowledge of travel technology - specifically airline and/or hotel distribution systems

## What you will do

- Communicate proactively with strategic customers as their primary point of contact at Duffel, keeping the customers engaged and maximizing the use of our services and solutions
- Manage the implementation process with a subset of Duffel customers as they build a travel experience on top of Duffel’s fulsome API tools
- Answer product questions and resolve API issues via email, slack, and zoom.
- Support the Duffel sales team on technical review calls with prospective customers
- Maintain deep technical knowledge of the Duffel platform to educate customers on best practices
- Establish and manage best practices to onboard and engage customers with sound and robust processes
- Develop KPIs with each customer to measure and optimize business and technical performance
- Analyse customers’ needs and advise how they can use our APIs to better meet them.
- Champion product needs within Duffel to inform our technology strategy and roadmap

What's in it for you:

- Work From Anywhere 🏡
- Duffel Travel Allowance ✈️
- Generous Parental Leave 👩‍🍼
- Sabbatical opportunities 🧘‍♀️
- x2 Days Hybrid at our Shoreditch office + team socials 🪩
- Competitive package + equity 💰

## What you can expect from us

We’re dedicated to your personal growth. Our environment is comfortable physically, but also in that our ears are always open to any ideas, concerns and questions. We believe that everyone should have pride in their work, taking full ownership of it and its impact. That’s why everyone who joins Duffel owns a share of the company.

We are an equal opportunities employer. We believe that the key to our success is employing a diverse team, that’s why recruitment decisions are only based on your experience and skills. We value your ability to problem solve and build amazing things so we welcome applications for everyone – regardless of age, sex, disability, sexual orientation, race, religion or belief.

Note to recruitment agencies

Duffel does not accept speculative CV's from external parties. Any unsolicited CV's sent to us will be treated as property of Duffel, and any attached terms and conditions associated with these CV's will be null and void.

## About Duffel

## Company Overview
- **One-liner**: Duffel provides easy-to-use APIs and software tools that allow any business to shop, book, and manage flights, hotel stays, and travel extras without the complexity of legacy travel infrastructure.
- **Entity Type**: Private (VC-backed; Series B)
- **Headquarters**: London, United Kingdom
- **Founded**: 2017
- **Founders**: Not publicly available (CEO is Steve Domin)

## Core Business
- **Primary Industries**: Travel technology, SaaS / API infrastructure
- **Target Customers**: B2B – startups, challenger banks, spend management platforms, and large enterprises that want to sell travel online
- **Mission / Purpose**: "To make travel effortless" by rebuilding the software layer that underpins the global travel industry [duffel.com/about-us](https://duffel.com/about-us)

## Products & Services
- **Flights API**: Complete flight shopping, booking, order management, and ancillaries (seats, bags) with access to global airline content via Duffel’s own accreditation and ticketing authority.
- **Stays API**: Earn commission on over 1 million properties worldwide; build hotel shopping experiences with rich content and loyalty benefits.
- **Ancillaries Component**: Pre-built UI for seat selection and baggage (and more) that can be dropped into any web or mobile experience.
- **Loyalty & Payments**: Features to offer loyalty programme perks and integrated payment flows.
- **Front-end Components**: Customisable, ready-made shopping interfaces (e.g., autocomplete flight search) for rapid integration.

All products are delivered as RESTful APIs with client libraries in Node.js, Python, and Ruby, plus comprehensive documentation and user guides [duffel.com](https://duffel.com/).

## Market Standing
- **Valuation**: Not disclosed
- **Key Metric**: Total funding – **$56.3M** raised across four rounds:
  - Seed (Aug 2018): $4.8M led by Blossom Capital
  - Series A (Jun 2019): $21.5M led by Benchmark
  - Series B (Oct 2019): $30M led by Index Ventures
  - An earlier $125K seed round (Sep 2018) also noted [linkedin.com](https://uk.linkedin.com/company/duffelhq)
- **Estimated Annual Revenue**: $1.4M (private company estimate, per LinkedIn data)
- **Notable Investors/Partners**: Benchmark, Index Ventures, Blossom Capital, Y Combinator (S18), Kima Ventures; partners include some of the world’s leading airlines.
- **Growth Signals**:
  - Headcount of ~41 employees (+16.1% YoY)
  - Active hiring in Engineering, Customer Success, and Partnerships (12 open positions as of mid-2026)
  - Operating in 5 countries (UK, US, Spain, South Africa, Denmark)
  - New product launches (Ancillaries component, Stays API, loyalty features) [linkedin.com](https://uk.linkedin.com/company/duffelhq)

## Competitive Advantages
- **Proprietary accreditation & ticketing authority** – enables direct access to global airline content without each customer needing their own license.
- **Developer-first approach** – modern, well-documented APIs with client libraries in multiple languages and pre-built UI components.
- **Full-stack travel platform** – covers flights, stays, ancillaries, and payments in a single integration.
- **Focus on rewriting legacy infrastructure** – removes the archaic software hurdles that have historically blocked new entrants from selling travel.

## Strategic Focus
- Deepen the product suite (rooms, ancillaries, loyalty) to become the single API layer for all travel.
- Expand into verticals like challenger banks and spend management (e.g., “Duffel for Spend Management”).
- Scale partnerships with more airlines and property providers globally.
- Continue hiring engineers and customer success teams to support enterprise clients and geographic expansion.

## Why Work Here
- **Hybrid & Flexible**: Office two days per week in London; 60 days per year work from anywhere globally.
- **Time Off & Leave**: 27 days annual leave plus public holidays; 26 weeks fully paid parental/adoption leave; 12-week sabbatical after 4 years.
- **Compensation & Equity**: Competitive base salary reviewed annually, stock options, pension match up to 5%.
- **Perks**: Duffel Travel Allowance (stipend to spend on flights), private healthcare, learning & development budget, up to 4 study days per year, paid volunteering day.
- **Engineering Culture**: Modern stack (Node.js, Python, Ruby, APIs), focus on AI and backend roles. Team alumni from Monzo, Deliveroo, GoCardless, and Paddle.
- **Interview Process**: Online application → recruiter call → first interview → final-stage interviews (typically a half-day on Zoom) [duffel.com/careers](https://duffel.com/careers).

## Sources
1. [duffel.com/about-us](https://duffel.com/about-us)
2. [duffel.com/careers](https://duffel.com/careers)
3. [duffel.com](https://duffel.com/)
4. [linkedin.com/company/duffelhq](https://uk.linkedin.com/company/duffelhq)
5. [jobs.lever.co/duffel](https://jobs.lever.co/duffel)

## Other roles at Duffel

- [Recruitment Lead](https://feeny.ai/job/recruitment-lead-duffel-london-37y3s8n9qrgt) — London, United Kingdom
- [Legal Counsel (Commercial)](https://feeny.ai/job/legal-counsel-commercial-duffel-london-yxxrhv1f0tvh) — London, United Kingdom
- [Head of Technical Support](https://feeny.ai/job/head-of-technical-support-duffel-london-fphs170ds4x9) — London, United Kingdom
- [Partner Engineer (Pre and Post Sales)](https://feeny.ai/job/partner-engineer-pre-and-post-sales-duffel-new-york-439k2r3jxrwb) — New York, NY
- [Product Manager - Flights](https://feeny.ai/job/product-manager-flights-duffel-london-ddv5rf4zk3j9) — London, United Kingdom
- [Product Manager - Payments](https://feeny.ai/job/product-manager-payments-duffel-london-dc49bcsrb1pk) — London, United Kingdom
- [Software Engineer  (Backend)](https://feeny.ai/job/software-engineer-backend-duffel-london-jsmzrzwag0yp) — London, United Kingdom
- [Travel Support Consultant, US](https://feeny.ai/job/travel-support-consultant-us-duffel-united-states-vxbpdej2d02p) — United States
- [Travel Support Consultant, London](https://feeny.ai/job/travel-support-consultant-london-duffel-london-h7pqzfj7d4n1) — London, United Kingdom