Senior Product Engineer (Backend)

Plain; Greater London; On-site; GBP 60,000 - 80,000; Full time

Job summary

A pioneering tech startup in Greater London is seeking a talented engineer to define product direction and shape backend architecture. This role is key in building solutions for customer problems and enhancing the developer experience. If you thrive in early-stage environments and have a proven track record in B2B SaaS, we want to hear from you. The ideal candidate will excel in both technical and customer discussions while driving impactful projects forward.

Qualifications

• Proven track record working for product-led companies, ideally in B2B SaaS.
• Experience with distributed, serverless systems.
• Ability to prioritize workload effectively.

Responsibilities

• Contribute to product direction through technical architecture and roadmap.
• Scope, build, and launch product features that solve customer problems.
• Shape backend architecture while tackling complex challenges.
• Enhance developer experience through effective tooling.

Skills

Problem-solving

Technical architecture

Customer feedback integration

Distributed systems

Web application performance

Autonomy

Job description

Plain is redefining customer support for the next generation of B2B companies. We’re building the fastest, most powerful platform to help companies move beyond reactive support and build true customer relationships.

Some of the world’s most forward-thinking companies - like Cursor, Raycast, and Granola - trust Plain to unify all customer interactions, enable faster team collaboration, and supercharge their workflows with AI.

B2B customer support is undergoing a seismic shift. AI is transforming the way companies engage with customers, shifting support from a siloed function to a company-wide effort across Slack, Discord, and any other channel you talk to customers in. The old way - slow, manual, and disconnected - no longer works.

What you'll do

Engineering at Plain is about much more than moving tickets from left to right - it’s about owning and solving problems end to end, from infrastructure decisions to feature design to button copy.

You will:

• Help set product direction. You’ll contribute to both the technical architecture and the roadmap, balancing customer feedback with long-term product health.

• Ship features end to end. You’ll scope, build, and launch product features that directly solve customer problems. We’re structured into the following teams right now:

  • Core Product: Own all customer-facing channels (Slack, Discord, Email, etc), core data models, and customer requests. You’ll balance moving fast to win customers with investing in strong foundations for the future.

  • Developer Infra: Build the tools that every engineer at Plain depends on to ship and operate the product. Your focus is on making the team faster, removing roadblocks before they happen, and ensuring everything we build is easy to run, debug, and control in production.

• Shape our backend architecture. You’ll tackle some of our most complex challenges, from data modeling to high-performance reporting, and help set the standard for how we build across the company.

• Create a stellar developer experience. From data pipelines to APIs, you’ll make sure Plain is not only great to use but also great to build on.

This is a great fit if you…

• Thrive in early ideation stages, love sharing work-in-progress, and enjoy the balance of making trade-offs in order to ship high impact products.

• Are impact driven and motivated by seeing customers succeed. You measure the quality of your work by the end-experience of users, not the abstractions or cleanliness of the code.

• Have a proven track record working for product-led companies, ideally in B2B SaaS.

• You’re autonomous and able to prioritise your workload. You know when to take a shortcut and when to invest in long-term infrastructure.

• Have experience working with distributed, serverless systems, and have worked on similar web applications with a high quality and performance bar before

• Are equally at home in architectural conversations as you are in customer conversations.

• Can learn new technologies and paradigms quickly and independently.

This won't be the right role if you…

• Are uncomfortable with ambiguity. We have some really exciting traction but are still at an early stage and are constantly learning and trying new things as our company grows.

• Find learning about new technologies a key motivation for coming to work. We invest in what makes us productive but will prefer the known option to the experimental and novel. Postgres is great.

• Are looking to manage others. We're firmly looking for someone who, for now, wants to be an individual contributor.

• Expect all the perks of a big company. We’re a Series A startup and are competitive in what we offer at our stage, but it’s a different role and opportunity than working at an established tech company.