Software Engineer (Full-Stack)

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

Job summary

A leading developer tools startup is looking for a Full-Stack Software Engineer to join their team in London. You'll work closely with experienced co-founders and be responsible for architecting innovative solutions that enhance developer productivity. Ideal candidates should thrive in dynamic environments and possess a strong background in full-stack development, particularly using technologies like Node.js and Next.js. Join us to help shape the future of developer tools and tackle challenging engineering problems.

Qualifications

• Experience in shipping production-level software.
• Genuine curiosity about product experiences leveraging AI.
• Previous founder or founding engineer preferred.

Responsibilities

• Architect our event-driven backend using Node.js and Next.js.
• Build a system of agents for enhanced user productivity.
• Create intuitive product interfaces for human-agent interactions.

Skills

Full-stack development

Node.js

Next.js

TypeScript

Event-driven systems

Communication

Job description

We’re looking for a Software Engineer (Full-Stack) to join our team in San Francisco, CA. We're focused on solving a big problem: how to make all the annoying tasks outside of your code editor fully agentic; everything from deployment to performance, incidents, and bugs.

You'll be working directly with me (Daniel). Before StarSling, I was the Engineering Manager at Netflix working on the most used internal tool for their 3K+ engineers and tens of thousands of microservices — an internal developer portal called Netflix Console. Earlier in my career I was an engineer on Facebook’s AI Camera team and helped build the mobile computer vision library that currently powers camera effects for 100M+ DAUs across IG, FB, and WhatsApp. I’m obsessed with helping every engineer be more productive.

You’ll also be working directly with my co-founder Yonas. Before StarSling, Yonas was the Founder & CEO of StackShare, a developer community used by over 40 million developers. He raised $12M as a first-time founder and did founder sales to get them to just under $1M ARR with their enterprise product before selling the company last year. He’s obsessed with creating product experiences that developers love and building community.

What You’ll Own

• Event-driven backend: Architect our Node.js / Next.js / TypeScript and Supabase stack. Design schemas, event flows and ingest dev tools webhooks to power a real-time personalized engineering portal.
• LLM Agentic Workflows: Build a system of agents — MCP, tool use, memory, retry logic, context updates, feedback mechanisms.
• Agent Experience (AX): Create intuitive product interfaces for human-agent interactions. Explore and iterate with engineers to find the right interaction paradigm to productivity work with a digital co-pilot.
• System Design & Technical Strategy: Work directly with me to determine the best technical path that balances moving fast and scaling to many customers using different dev tools. Determine how we integrate and support the open-source community.

This IS for you if

• You’re a full-stack 0-to-1 builder who has shipped to production. Especially in rapidly shipping NextJS apps and working with event-based systems in a serverless architecture.
• You have a genuine curiosity about agentic product experiences and are excited about understanding the impact of AI on engineering users.
• You’re a previous founder or founding engineer. You have built something from scratch that people use or pay for.
• You’re unusually obsessed with hard problems. Your current skills or even what you've done before is less important than your ability to go all-in and accomplish anything that you set your mind to.
• You’re comfortable with ambiguity and adapting to dynamic priorities. You need to have good judgement to know when to let little fires burn and when to immediately jump in.
• You have excellent communication and candor. You’ll be communicating directly with engineers and collaborating with us on key decisions.
• You care about helping swamped engineers fight through the schlep of software development. If that's not an exciting mission for you, it will be hard to stay motivated through the inevitable highs and lows.
• You have grit and perseverance. You should accustomed to picking between hard options and pushing through it.

This IS NOT for you if

• You’re not based in The Bay Area (we’ll be a team of three if you join so we’ll be sitting next to each other in San Francisco everyday)
• You’re not willing to work six days per week (we take Sundays off)
• You’re not excited about using codegen tools like Cursor, Windsurf, Claude Code, etc.
• You’re not comfortable deleting 80%-90% of the code that you write.
• You’re not comfortable with ambiguity and rapid context-switching.
• You don’t like candor- receiving and giving direct, honest feedback.
• You need a well defined structure or career ladder.

The Opportunity

• Work alongside two experienced co-founders - one who built and sold a dev tools startup and one who led the engineering effort to create the same product we’re creating at scale
• Get experience across the startup stack - you’ll be doing customer support, bug squashing, user interviews, events, and everything else along with writing code
• Be one of the first employees of the next dev tools category leader - we’re not just building a dev tool, we’re building an engineering platform that every company in Silicon Valley will be using and paying for