Product Engineer

Honest Mobile; Greater London; Hybrid; GBP 70,000 - 90,000; Full time

Benefits offered by this job

Hybrid-first working environment

EMI option scheme

33 days annual leave

Birthday leave

Learning budget £500

Private medical insurance

Cycle to Work

Team socials

Job summary

Honest is seeking a Product Engineer focused on customer features and platform iteration. You’ll work across mobile app development, dashboards, APIs and cloud infrastructure as part of our mission to improve signal and reliability.

You’ll guide AI-driven execution, write clear specifications and collaborate with product, engineering and support teams. This role emphasizes delivery speed, maintainability and customer impact in a hybrid London-based environment.

Qualifications

• Experience turning customer needs into platform features.
• Ability to write clear, unambiguous specs and tests for AI execution.
• Strong cloud and networking skills to support infrastructure improvements.
• Ability to balance delivery velocity with reliability and maintainability.

Responsibilities

• Collaborate on platform infrastructure and feature development, defining scope and timelines.
• Communicate with internal teams to understand pain points and translate them into solutions.
• Write clear specifications and test plans for AI-driven work.
• Direct AI to build, test and iterate, reviewing outputs against the spec.
• Improve CI/CD pipelines and deployment strategies for reliable delivery.
• Set up observability, alerting and incident response to protect uptime.
• Contribute to data infrastructure and pipelines for reliability.

Skills

Customer-facing features

AI as execution partner

Specification writing

Cloud infrastructure

Networking

Collaborative teamwork

Job description

Hello, we’re Honest.

The clue’s in the name: we’re the network doing mobile right.

We’re on a mission to set a bold new standard for mobile (and drag a broken industry into the future while we're at it).

It started with Classic SIM, our essential everyday SIM that includes bills that drop, support in seconds, and a shrinking carbon footprint.

Thousands of happy customers joined us. But we knew people still faced two big problems: rubbish signal and expensive roaming.

So we built Smart SIM, our game-changing back‑up eSIM giving you unbeatable signal and free global roaming. Whenever you lose signal or go abroad, you can switch to Smart SIM in just a few taps for 500+ essential apps on EE, O2, Three and Vodafone, plus hundreds of networks worldwide.

Now we're proud to have more than 100,000 customers on our journey.

We’re also the UK’s first B Corp mobile network, a carbon‑negative company and member of 1% for the Planet

But building the world’s best mobile network requires having the right people to help us do it. That’s where you could come in.

Like the sound of Honest? Read on. This could be the start of something exciting

Role overview

We’re looking for a Product Engineer to focus on customer features and platform iteration. You’ll collaborate with the team to evolve our platform, including mobile app development, internal dashboards, API and MCP services, networking and cloud infrastructure as part of our broader mission.

Your work directly impacts our customers and fellow engineers. Your job is to improve the platform and build features that make everyone’s lives easier, contributing to infrastructure and reliability tasks when needed to keep the team shipping faster.

This is a role focused on iteration and delivery. You’ll help decide what to build, scope it, and direct AI to implement it. AI is your primary execution mechanism. The value you bring is judgement: what features to prioritise and how to iterate effectively on the platform.

You’ll balance operational tasks with product velocity. Every contribution affects our ability to ship, so prioritising developer experience and customer‑facing improvements is the heart of the role.

What you’ll do

• Collaborate with the team on platform infrastructure and feature development, helping set timelines and defining scope for new iterations
• Talk to internal customers (product engineering, marketing and the customer support team) to understand the real pain before specifying solutions
• Write specifications that are clear, complete and unambiguous enough for AI to produce correct output
• Direct AI to build, test and iterate, then review every output against the spec and architectural intent
• Iterate on cloud infrastructure-as-code to support new customer features while maintaining security and efficiency
• Assist with networking and infrastructure troubleshooting, tasks, and improvements on an as‑needed basis
• Contribute to CI/CD pipelines and deployment strategies to ensure a smooth and reliable delivery process for the whole team
• Set up alerting, observability and incident response that catches issues before customers do
• Support data infrastructure and pipelines to ensure platform reliability and data availability
• Spot recurring operational burden and decide what to automate vs what needs structural investment
• After shipping, verify it solved the problem, spending more time on the bigger or riskier changes. Then close the loop: tell the person who asked and make sure they can actually use the result, not just that the ticket’s closed.
• Contribute to improving our AI development process: when AI produces incorrect output, trace back to the missing constraint, fix it, then fix the output, so the system gets sharper over time

About you

• You prioritise customer‑facing features and platform iteration, and you understand the domain well enough to specify it cleanly
• You treat AI as an execution partner: you direct it, review its work, and encode what you learn back into the system so the next session is sharper
• You write specifications and tests that are clear, complete and unambiguous, because you know the quality of the spec determines the quality of everything downstream
• You have a strong background in platform development and can leverage your cloud and networking skills to assist with infrastructure improvements
• You understand that infrastructure isn’t built for itself: every decision affects the team’s ability to ship product work
• You are collaborative and outcomes‑oriented, working with the team to hit milestones and flag risks early
• You thrive in a collaborative environment where decisions are shared and the focus is on the best path forward for the product
• You measure success by uptime, reliability and how easy you’ve made the team’s life, not by volume of code shipped
• You know when to push through yourself and when to bring in deeper expertise
• You care about clean, maintainable, well‑documented work, even when you’re moving fast
• You communicate clearly, challenge assumptions confidently and ask great questions

What's it really like to work in Product Engineering at Honest?

Honest by name, honest by nature. We like to be upfront about how we work, so here’s what you need to know.

Life in our product engineering team moves fast. Priorities shift, ideas evolve, and plans change as we stay nimble and focused on what matters most.

Honest is a place for people who enjoy adapting, thinking on their feet, and learning as they go. What you’re building today might look different tomorrow, not because it was wrong, but because we’ve found a better way forward.

No two days are the same. It’s dynamic and exciting, and best suited to engineers who thrive in fast‑paced environments and see change as an opportunity, not a blocker.

We’re building something new together from the ground up. Ready to join the fun?

Interview process

• Introductory call with Fi, our Head of People & Impact (20-30 mins)
• First round interview with Ben, our Head of Engineering (45 mins)
• Practical technical interview with Ben and Sib, (1.5hrs)
• Values interview with Andy and Josh, our Co‑Founders (1hr)

Support during the process

If you have a disability, health condition, or any access needs and would like us to make adjustments to our process, please let us know. We’re happy to work with you to make sure you have what you need to take part fully and comfortably. Email Fi, our Head of People & Impact. She’s here to help.

UK work eligibility

We can only accept applications from those eligible to live and work in the UK. We are unable to sponsor visas for this position.

What you’ll get in return for all your hard work?

• Salary: £70,000 - £90,000
• Ownership in Honest through our EMI option scheme
• 33 days of annual leave including all the bank holidays + an extra day each year you stay with Honest
• Your birthday off each year on us!
• A hybrid‑first working environment with at least 1 day per week in the London office
• An Honest sim, and refurb phone on us
• 1 paid volunteering day each year
• Wellbeing budget through Heka
• Cycle to Work scheme
• £500 annual learning budget
• Regular in‑person team socials
• Private medical insurance
• Group Life insurance
• Enhanced and inclusive parental leave
• Dedicated period and menopause leave

Why join Honest?

Backed by top investors including DMGV, WAYRA, Ascension and TinyVC

Being part of a talented team that likes to have fun

Fast‑learning, entrepreneurial environment where we focus on supporting your growth and personal development

Opportunity to help shape the future of Honest

We’ll provide you with all the tools and technology you need to do your best work

Working for one of the UK’s top rated mobile networks on Trustpilot

Make your mark at the UK’s most ethically rated and highest scoring B Corp mobile network

Diversity, inclusion, equity and belonging at Honest

Here at Honest, we’re all about doing the right thing, especially when no one’s looking.

That includes building an inclusive environment where everyone feels like they belong and proud to be their true selves everyday. We’re committed to providing the support our team needs to thrive and do their best work.

We believe it’s our differences that make us stronger and celebrate diversity in the Honest team. Learning from one another’s unique experiences, perspectives and ideas is how we win.

That’s why we strongly encourage applications from all walks of life. So no matter your ethnicity, sexuality, gender identity, disability, neurodiversity, caregiver status, economic background or anything else, we welcome your application.